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CYCLOPEDIA 

OF 

Bricklaying, Stone Masonry, Concretes, 
Stuccos and Plasters 

BRICKLAYING 

It gives details relative to sinking shafts, excavating, foun¬ 
dations, walls, cornices; all about bonding, chimney 
breasts, flues, stacks and fireplaces, arches, joints, etc. 


STONE MASONRY 

Complete instructions as regards methods of building walls 
in rustic rubble or square rubble. Irregular corners, and 
other styles of work. Finished stones, such as window 
sills, coping, arch stones, key stones, and other dressings 
are described and illustrated. 


CONCRETES AND CEMENTS 

Are fully treated, including reinforced concrete, and the 
latest methods of making and using hollow cement building 
blocks, concrete sidewalks, foundations, stairs, floors and 
ceilings, facing and coloring concretes, etc. 


MORTARS, PLASTERING and STUCCO WORK 

Are covered in detail. The best methods .of making and 
using them are described and illustrated in a clear and 
simple manner. 


FULLY ILLUSTRATED 


By ERED T. HODGSON 

Special Exclusive Edition 
Printed by 

FREDERICK J. DRAKE & CO. 

EXPRESSLY FOR 

SEARS, ROEBUCK & COMPANY 

CHICAGO, ILL. 

1914 










TH 

• Hi 

\3 \*t 


Copyright 1913 

BY 

FREDERICK J. DRAKE & CO. 


Copyright 1914 

BY 

FREDERICK J. DRAKE & CO. 



NOV 30 1914 

©CI.A387773 

■Ke , 









PREFACE 

While the mason, the worker in cut stone, is generally 
supposed to be a more skillful and a more artistic 
workman and as a rule takes precedence over the man 
who works in brick alone, I have in this work dared 
to reverse this order and devote the first part of this 
volume to enhance the interest of the worker in the 
more humble but certainly more useful material—• 
brick. 

When bricks were first employed as building mate¬ 
rial matters but little to the practical workman,, but 
that bricks "were employed before history was written 
may be accepted as a fact, for we have evidence of it 
in many parts of the world; and whether brick or 
stone was first used in the construction of habitations 
for man need not trouble us at this late date. 

What we moderns want to know is, '‘how to make 
better bricks than were ever before made and how to 
handle them so as to make solid, artistic and eco¬ 
nomical brickwork”; and to this end this volume, or 
rather this first part of the volume, is devoted—not, I 
hope, without some success. Of course, in a volume 
of this kind, which is intended altogether to show in 
the clearest possible manner the various methods 
employed in the trade, it is quite natural that I should, 
in a great measure, follow in the footsteps of other 
writers, and I may say right here that besides adding 
some matter drawn from my own experience, I have 
taken much of the material used from some of the 
very best authorities who have written on the subject, 

9 


10 


PREFACE 


among whom may be mentioned Gwilt, Nicholson, 
Ferguson, Weale, Encyclopedia Britannica, Parker, 
Scott, Burn, Trautwine, Mitchell, Richards, Ward 
Lock & Co.’s works, Lynch, Hammond, Sheldon, 
Powell, Rivington’s Construction, Baker, Kidder, 
Knight’s Mechanical Dictionary, Magginis, and many 
other noted writers on bricks and brickwork. The 
various magazines devoted to architecture and building 
have also furnished me with many of the items, ideas 
and illustrations that will be found in the work, and I 
name some of the most prominent of the journals from 
which I have made copious extracts: “American 
Architect,” “Canadian Architect,” “Architects and 
Builders’ Magazine,” “Inland Architect,” “National 
Builder,” “Carpentry and Building,” “Building 
World,” “Illustrated Carpenter and Builder,” “The 
Builder,” “The Building News,” “The Architect,” 
besides selections from many other sources. 


BRICKLAYERS’ GUIDE 


FOR THE BRICKLAYER 


SOME DEFINITIONS 

Throughout this work the terms “plan,” “elevation’' 


constantly used, and 


for 

A 


the 


Fig. 


and “section”' will be 
benefit of those who 
do not understand 
these terms the fol¬ 
lowing definitions are 
intended: C 

Plan .—A plan is a 
drawing representing 
any object as it would 
appear when looking down upon it. Thus, in drawing 
the plan of an 18 -in. wall, not including the footings, 
draw the outside face lines and joints as in Fig. I. 

Elevation. —Anele- 
bBK’- —^ vation is the view of 

any object when 
q looking directly at it. 
It may be vertical, 
or at any inclination 
to the horizontal 
plane. Elevations 
are known as front, 
back,and side; hence, 
again illustrating by means of the 18 -in. wall, the front 
and back elevations would be shown as in Fig. 2 . 


1 , 

I i i 

1 1 r 1 

T H 

! 

1 1 1 

11 , i 

TTTTTTl 

1 

Vk V i 

IT 1 

1 h-LH I I I I 

i 

■* 


B 


Fig. 2. 























12 


BRICKLAYERS’ GUIDE 


Section. —A section is the view of an object repre¬ 
senting it as it would appear when cut horizontally or 
vertically by a plane parallel or at any angle to the 
face or end. For instance, a vertical section, A B, 
through Fig. 2 would appear as Fig. 3. 

Course. —A course is the name given to one row of 
bricks, in any thickness of wall, between two bed 
joints, as C D, Fig. 2. 

Bed Joints. —These are the mortar joints between the 
courses, as E F, Fig. 2. 

Cross Joints. —The short vertical joints at right 
angles to and connecting the bed joints 
are known as cross joints or perpends 
(see G H, Fig. 2). 

Tramverse Joints. —When the cross 
joints are continued through the thick¬ 
ness of the wall they are called trans¬ 
verse joints, as A B, Fig. 1. 

Wall Joints. —These are the joints in 
the thickness of and parallel to the 
face of the wall C D, Fig. 1. 

Quoins. —The external angles of a wall are called 
quoins (see I J, Fig. 2). 

Stretcher. —This is the 9-in. face of a brick, K, 
Fig. 2. 

Header. —The 4^-in. end of a brick, L (see Fig. 2). 

Bats. —The half of a brick is known as a 4^-1’n. bat, 
while any length above this and below 9 in. is known 
as a three-quarter bat. 

Lap.— The horizontal distance between the cross 
joints in two successive courses is called the lap. This 
should never be less than one-quarter of the length of 
the stretcher, X, Fig.. 2. 

Closers [Kings and Queens).— A king closer is a brick 










FOUNDATION 


13 

made to appear as a header on one end and a closer 
on the other (Fig. 4). 

A queen closer is a brick cut, if possible, 9 in. in 
length by 2^ in. on the face; most usually the 9 in. 
are made up of two 4^-in. lengths (Fig. 1). 

Besides these, there are other closers that will be 
described later on. 

The average length of a brick is 8 % in., but with 
the addition of either a cross joint or a wall joint it is 
reckoned as 9 in. 

The width is 4^ in , and for the same reason as 
given above it is considered to be 4>4 in. 

The average thickness is 2^ in , and four courses 
with the bed joints will 
measure 11^ in., 12 in., 
or 12^4 in., etc., according 
to the thickness of the 
joints. 

The usual practice is to 
build the work four courses 
to a foot. 

A wall i 1 /^ bricks thick 
is usually called a 14-in. 
wall, 2 y 2 bricks thick a 23-in. wall, whereas walls 2 
bricks and 3 bricks thick are known as 18-in. and 27-in. 
walls, respectively. 

FOUNDATIONS 

The first thing to be considered in any brick struc¬ 
ture is the foundation, and it is but proper we should 
devote some space at the outset to this important part 
of the subject. First we have, the necessity for foun¬ 
dations. Walls of buildings resting on ground of 
variable strength often fracture, due to the unequal 







14 


BRICKLAYERS’ GUIDE 


settlement of the work. To prevent failure in this 
manner the base of the walls of the building may be 
extended and supported by suitable foundations. 

The object of foundations is to prevent inequality of 
settlement and distribute the weight of the structure 
equally over the substratum. 

The bases of structures are invariably made wider 
than the superincumbent mass, to increase the stability 
and to counteract all the following damaging forces 
that tend to cause failure. 

Damaging Forces.—The principal causes of failure are 
those which induce settlement, such as inequalities of 
earth resistance; the compressibility of mortar joints; 
lateral escape of soft soil, sliding of the substratum on 
sloping ground; the withdrawal of water; distributed 
lateral pressures, causing overturn, such as wind 
pressure, and thrust of barrel vaulting or of an untied 
couple raftered roof; concentrated lateral pressure 
which induces settlement and overturn, such as the 
thrust of framed floors, trussed roofs and groined 
vaults subjecting small areas of support to great 
pressures. 

Inequality of Settlement.—Inequality of settlement in 
buildings takes place from two causes: (i) the com¬ 
pressibility of the mortar joints, (2) the compressi¬ 
bility of the soil. 

An allowance of 1 in. in 24 ft. of brickwork in lime 
mortar is often provided for settlement, as in the 
example of the extremities of bridging joists of floors, 
at one end being supported by a brick wall and the 
other extremities by iron columns, etc. 

Nearly all soils, with the exception of solid rock and 
gravel, are compressible under pressures often attained 
in buildings. It is therefore impossible, where large 


FOUNDATION 


15 

buildings are erected on other soils, to avoid settle¬ 
ment; and the fact of any building settling is of no 
great import, provided the settlement be uniform and 
of no great depth, and the relative position of the 
parts of the structure unaltered. But where the resist¬ 
ance of the soil of every part of the site is not uniform, 
there is a risk of the above defect occurring, and 
special precautions must be taken to distribute the 
pressure to suit the varying strengths of the sub¬ 
stratum. 

Lateral Escape.—Heavy structures erected upon soft 
soils, such as running sands and peat, squeeze out 
from beneath the foundation, unless means are taken 
to confine the soil to the required area; this is usually 
accomplished by sheet piling, as described later. 

Sliding.—This is a defect usually occurring where the 
building is erected on the slope of a hill, and the strata 
inclined, being depressed in the direction and towards 
the bottom of the slope. The weight of the building 
is liable to cause the strata to become detached and 
slide. This is prevented in two ways: (1) by driving 
piles at intervals to a considerable depth, thus con¬ 
necting the strata; this method is often objectionable, 
tending, as it does, to shake and disturb the soil; (2) 
by building a retaining wall; this is the better method, 
as it not only supports, but also protects the strata 
from the effects of the atmosphere, which in soils 
easily affected by the latter is a desideratum. 

Withdrawal of Water from Foundation Earth.—Edifices 
built on damp soil, such as a sand overlying a clay, 
have their stability endangered should the water be 
drained away after the building has been erected, as 
it will cause the foundation earth to occupy a less 
volume and in the sinking will tend to fracture or 


i6 


BRICKLAYERS’ GUIDE 


overturn the walls; therefore the depth of the concrete 
foundation must be arranged below any probably 
adjacent cutting. 

Distributed Overturning Pressures.—Distributed forces 
acting upon the upper level of walls, such as the con¬ 
tinuous pressure of barrel vaulting and the spreading 
tendencies of untied couple raftered roofs, and also 
the distributed pressures on wall faces, such as wind 
pressure, tend to cause failure in two ways: (i) by 
overturning, the minimum resistance being generally 
at the change of section, usually at the ground level; 
(2) by subjecting the leeward edge of the wall to the 
pressure sufficient to crush the material or by throw¬ 
ing the weight on a small area of the substratum, forc¬ 
ing it from its original position and causing a 
settlement. 

The stability of walls when subjected to such dis¬ 
tributed overturning pressures is treated in the chapter 
on that subject.. 

Concentrated Lateral Pressure.—The thrust caused by 
united principals', as groined faults or other forces act¬ 
ing at a point or along vertical lines on the wall, are 
often resisted by buttresses. 

Atmospheric Action. —Many otherwise thoroughly 
reliable soils are practically reduced to the condition 
of mud if exposed to the effects of the atmosphere or 
to rain water. The variation in temperature at the* 
different seasons also causes the ground to expand and 
contract considerably. 

Where foundations are constructed in such soils, 
they must be taken sufficiently deep to be beyond the 
effects of the atmosphere, that is, below the line of 
saturation. Four feet below the ground level is usually 
sufficient for this purpose, the soil below this not being 


FOUNDATION 


17 

affected to any appreciable extent by the percolation 
and subsequent freezing of rain water. 

'The line of saturation in the section of any part of 
the earth’s crust represents the depth to which the soil 
at that part is saturated by the absorption of rain 
water and affected by atmospheric changes. 

Excavations.—Before commencing any constructional 
work in connection with a building it is necessary as 
the first operation to carefully take the levels of the 
site, in order first to arrive at an estimate of the 
amount of earthwork to be done; and secondly, to 
determine the design of the basement story, this latter 
often being materially affected if the differences in 
level of the various parts of the site are great. The 
next operation is to level the ground. This in most 
instances consists in excavating and removing parts of 
the site, and in depositing earth in other parts to form 
embankments or to fill up hollow places. In order to 
conduct these operations in the most economical man¬ 
ner the levels must in all instances be taken and 
plotted with the greatest accuracy. This can only be 
efficiently done on areas of any magnitude by means 
of the surveyor’s level, the method of employing which 
will be described later. All leveling operations for 
ordinary constructional work may be carried out by 
referring them to the principles laid down for per¬ 
forming the three following operations: 

1. Taking levels of site. 

2. Leveling the bottoms of trenches for drains or 
foundations. 

3. Embanking for roads or leveling of depres¬ 
sions. 

Instruments.—The instruments required to determine 
the levels of the site are: first, the surveyor’s level; 


i8 


BRICKLAYERS’ GUIDE 


second, the measuring staff; third, ranging poles and 
chain or tape. 

Methods of Leveling.—Taking the levels of a site may 
be carried out in one of three ways: First, by taking 
a number of section lines across the site; secondly, by 
erecting the level in a commanding position and tak¬ 
ing the relative heights of the salient points and noting 
them on plan (this method is only applicable for small 
sites); thirdly, by contours. 

In all three methods it is necessary to have a datum 
level to commence from, and from which all other 
levels can be referred. A line on some permanent 
structure in the immediate vicinity is usually taken, 
or if such does not exist, a stout stake is driven in the 
ground in a position away from the work where it is 
not likely to be disturbed. 

First Method.—A number of sections are ranged 
across the site, each line being numbered or lettered; 
the level is then set up on or in close proximity to the 
first line and the datum; the measuring staff is then 
held by an assistant on the datum point and then on 
the extremity of the line, the relative heights of the 
two points being recorded in a field book kept for that 
purpose. A number of points on the line are then 
taken, and the measuring staff is held over them and 
their relative heights are recorded, and their distances 
from the beginning of the line are measured. When 
the bottom of the measuring staff rises above or the 
top becomes depressed below the line of sight through 
the rise or depression of the ground, the level must 
be moved further along the line and the preceding 
operations repeated. Fig. 5 illustrates the method. 
The following is a form of field book with the reading 
for a section entered: 


FOUNDATION 

BackS/aA/ ZnTerm ed/a/e ^ * 

' d s/ghr. r 's - 5 


19 


is ye/. Zpre^S/ghf Measur/ng S/a/R 



D/a gram sAo/v/ng 
cZ ZeveZZ/Ag a sec//on 

'gAZ Ara/Zs 



1 ^////^ ? v/ra//* 


V 


Fig. 7. 


Fig. 6 . | j p 

k/VW/W/M 

S/gAZ A?a/Z w/ZA ZB>s/s 


I f 

I I 

^ 1 ? 

W 77 r/r>rr> 

S/gA/Z Atb/Z tv//A /-&sZ> 


A/'xed in d>round p Jcr . g ZxecZ in cZra/n gi/gies 



\Boning /rods 


S/gAZ Arbi/• 


7A~ 


VTf 

Bon/ng AoZZo /77 oZ 7Zync/i Arom S/gAZ ABa/As 

Fig 9 . 

Li* 



Boning Rods Z/X&ci ZncA/caZ/ng 
/eve/ for Z0/7 oZ embankment 

METHOD OF LEVELING 





















































20 


BRICKLAYERS’ GUIDE 


AFIELD LEVEL BOOK 


'Jack 

Sight. 

Inter. 

Sight. 

Fore- 

Sight. 

Rise. 

Fall. 

Reduced 

Levels. 

Dis¬ 

tance. 

Total 

Dis¬ 

tance. 

Remarks. 







chains 



4.15 





lOO'.O 



Bench Mark A 


4. L3 


.02 


100.02 

1 


1 peg 


5.01 



' .88 

99.14 

2 


2 


4.86 


.15 


99.29 

3 


3 


6.06 



1.20 

98.09 

4 


4 



8.02 


1.96 

96.13 

5 


5 

12.25 









8.46 


3.79 


99.92 

6 


6 


3.04 


5.42 


105.34 

7 


7 



2.15 

.89 


106.23 

7.57 


Bench Mark B 

12.60 










7.19 


5.41 


111.64 

8.57 


8 



”2*53 

4.66 


116.30 

9.57 


9 

9.37 









. 

5.75 

. 

3.62 


119.92 

10.57 


10 



3.94 

1.81 


121.73 

11.57 

11.57 

Bench MarkC 




25.77 

4.04 

21.73 







4.04 









21.73 







The above shows a typical field book. The reduced 
level of the first point is taken as ioo ft. above a 
datum level; the levels are all read in feet and hun- 
diedths of a foot; the distances are taken in chains 
and links, but may be taken in feet and inches. The 
rise and fall columns should be balanced, also the first 
and last reading in the reduced levels; these two 
quantities will equal each other if the computations 
have been correctly made. 

Second Method.— The second method is evident from 
the previous explanations. 

Third Method.— The method of contouring is the 
most useful, but takes the longest tim^ to perform it; 






































FOUNDATION 


21 


it consists in describing upon a plan a series of level 
lines with a uniform vertical interval between them. 
To carry out this operation it is usual to erect the 
instrument on the highest point of any section of ihe 
area to be contoured, and from this point to range a 
number of lines radiating from it, their direction being 
fixed by taking their bearings. The height of the 
instrument is then taken, and the man with the meas¬ 
uring staff is directed up or down each line in succes¬ 
sion until a number of points of the required vertical 
interval and their distances from the initial point are 
determined. This method is most useful for laying 
out large estates where extensive works are projected, 
as on such a plan the problems of drainage and roads 
of convenient and economical gradients can easily be 
laid down. 

When the levels of a site are known, and the build¬ 
ing is planned, and the position of one of its leading 
lines is determined, to set out the remaining lines of 
an ordinary building becomes a simple matter, only 
requiring great care in the measurements of the parts. 
If the setting out is rendered difficult through differ¬ 
ences of level in the paths, a theodolite would very 
much simplify the operations. 

Boning Method of Leveling. —This operation is used 
for the leveling of trenches, ground work, paving, etc. 
There are three rods in a set; two of these are leveled 
at a distance of about io ft. apart; a third .rod is then 
leveled at a similar distance, taking care to reverse the 
long level. The center rod is then removed, and the 
level transmitted to any point along the line by sight¬ 
ing or boning over the first and third rods. 

Fig. io shows the method of using boning rods and 
setting a curbstone. 


22 


* BRICKLAYERS’ GUIDE 


Trenching.—When the lines of the building have 
been laid down and all its salient angles pegged out, 
the work of excavating the trenches commences. It 
is absolutely necessary that the trenches should be 
level along their bottoms. To ensure this, two or 
more sight rails (as shown in Figs. 6 and 7) are erected 
over the trench; it is necessary that the side posts of 
these should be fixed in such a position that they shall 
not be disturbed by any of the subsequent operations. 



A level line is sighted through the level and marked 
on the sight rails; the cross bar is then fixed on each, 
and a mark is made on the bars plumb over the center 
of the trench. The width of the trench is marked out 
with the line and pins (see Fig. 9), and the excava¬ 
tion is carried on, timbering being inserted as the 
earth is removed, if required, by one of the methods 
afterwards described. When the full depth of the 
trench has been nearly reached, a number of points 


FOUNDATION 


23 


are sunk to the exact depth by means of boning rods, 
the top of which is sighted between two of the sight 
rails, as shown in Fig. 8. The remaining parts of the 
trench bottom are then taken out level between the 
points so determined. A similar process is pursued 
for sinking a trench for a drain, the variation being 
that the sight rails have a difference in height neces¬ 
sary to give the required fall. 

Embanking. —The method of forming an embank¬ 
ment is as follows: • The center line of the proposed 
work is ranged out on the ground, and at equal inter¬ 
vals along the line boning rods are erected, the two 
extreme rods being first fixed either level or with a 
difference in height sufficient to give the required 
gradient; a rod is then erected on each of the intervals 
determined upon, and boned between the two extreme 
rods. The embankment is then commenced from one 
end, the earth being tipped in from carts or wagons 
until the tops of the boning rods are reached; sufficient 
earth in excess must be allowed for to compensate for 
compression and settlement. The width of the em¬ 
bankment is completed as the work is pushed forward, 
as shown in Fig. 9. 

Timbering for Excavations. —It becomes necessary, 
where earth has to be excavated to any considerable 
depth, for foundations or other purposes, to support 
the sides of the cutting until the sinkings or trenches 
are filled in, or other action taken to permanently 
support the sides. This end is attained by means of 
timber shores, the arrangement of which is modified 
and governed by several conditions, such as the nature 
of the soil, the size of the cutting, and the special 
peculiarities of the particular piece of work under 
consideration. 


24 


BRICKLAYERS’ GUIDE 


There are three typical methods of strutting used 
for supporting the sides of narrow trenches excavated 






































FOUNDATION 


25 


The first, used for firm ground, consists of short 
upright members, termed poling boards, out of 
9x1^ in., usually from 3 to 8 ft. long, placed in posi¬ 
tion in pairs, one board on each side of the cutting; 
these are kept apart by struts out of about 4 x 4 in., or 
short ends of scaffold poles cut and driven tightly 
between the poling boards. The strutting is fixed as 
soon as the trench has been made sufficiently deep. 
The horizontal distance apart between the adjacent 
system of strutting varies according to the cohesive 
strength of the soil, but never less than 6 ft., which is 
just sufficient to allow a man to work in with effect. 

The method shown in Fig. 12 is adopted where the 
earth requires to be supported at shorter intervals than 
6 ft., and consists of upright poling boards and struts 
as before, but with the addition of a horizontal timber 
termed a waling piece. The process of fixing is as 
follows: The cutting is made, commencing at one 
end, and as soon as sufficient earth has been excavated 
a pair of poling boards and struts is inserted as in the 
first method; this process is repeated, fresh poling 
boards being fixed at distances apart varying with the 
nature of the earth, these distances being in some 
instances very short. 

Horizontal members, 4 x 4 in. or upwards, are placed 
one on each side of cutting and strutted tightly against 
the poling boards. After about 12 ft. has been thus 
cleared, the struts which were fixed first are then 
knocked out; a fresh depth is commenced, and treated 
in a similar way. 

The third method is employed where the earth is 
very soft, and consists in laying horizontally boards, 
usually 9x1^ in., against the sides of the excavation; 
the boarding laid in this manner is termed sheeting, 


26 


BRICKLAYERS’ GUIDE 


which is supported by upright poling boards and struts, 
as shown in Fig. 13. The method of fixing is as fol¬ 
lows: The earth is taken out to a depth of 9 in., and 
a pair of boards is inserted and strutted apart; another 
depth of 9 in. is then taken out, and sheeting fixed as 
before. This process is repeated until a sufficient 
number of boards has been inserted, usually four; 
upright poling boards are then placed in position 
against the sheeting and strutted apart, as shown in 
Figs. 9 and 10; the first fixed struts are now struck 
and cleared away. 

The above system may be improved upon, when the 
depth of the cutting is not too great, by cutting the 
sides of the excavation to a slight batter, as shown in 
Fig. 14; by so doing tlu timbers are prevented from 
falling should the earth contract on becoming drained; 
it also facilitates the fixing of the struts. 

Large Cuttings.—Continuous trenches, if made in 
bad ground, are generally arranged as shown in Fig. 
15. At intervals guide piles are driven in, to which 
walings are bolted, and sheeting consisting of boards 
about 10 ft. long, shod with iron, termed runners, 
inserted between; these are driven a short distance 
into the ground, the earth between the two systems of 
piles being then taken out, and care taken not to 
excavate within a foot of the bottom end of the runners, 
which are again driven in and the process repeated. 
After the excavation of the first part, wales, consisting 
of whole timbers, are placed in position and strutted 
apart, the struts being also of balk timber. Long 
struts are supported in the direction of their length by 
short uprights secured to them by dogs. Uprights are 
also placed between the waling pieces as each fresh 
one is inserted. 


FOUNDATION 


27 




























28 


BRICKLAYERS’ GUIDE 


After the ground has been excavated to the depth 
of the runners, a fresh system of piles and runners is 
driver slightly to advance of the former system, and 
the grouna excavated as before. Cuttings are made 
in firm ground by excavating the earth and using ordi¬ 



nary sheeting, but if the cuttings are required to 
exceed 30 ft. in width, it is found to be more eco¬ 
nomical to adopt a system of raking shores. 

The method illustrated in Figs. 16 and 18 is 
employed Vhere the ground is soft and waterlogged 





























FOUNDATION 


2g 



7x la Poling Boards. 



'srf 


X 




9x9' 


^t-xIZ Wa/ings. 

tt n 

9x3 Runners. 


i t 


3 Wedge 3. 


■J 

n-i 


/ if 


8-0 


L- 


Pig- 17/ 


r 




p 

f. 

i 

i 

7 I * 
on 

’ > 

1 

4 

/ * 

-0 

’ 



I 

<rtC. 

■ • 

. 

ggjjgfc.- - 



s 


s 




















































30 


BRICKLAYERS’ GUIDE 


and is especially suitable for running sand. By this 
method as much of the earth is taken out as is possible 
without the sides of the excavation falling in, gener¬ 
ally from 4 to 6 ft.; this is then supported by upright 
sheeting, waled and strutted. The excavation is con¬ 
tinued by lining the cutting with a secondary system 
of runner, i.e., battens 7x2 in., pointed at lower ends 



Fig. 18. 


and of about 9 ft. in length. These are waled and 
strutted. Between each runner and waling piece a 
wedge is inserted. The method of proceeding with 
the excavation is as follows: The wedges securing one 
runnel are loosened, the earth from the foot removed 
to a depth of about 12 in., the runner being dropped as 
the ground is removed and re-wedged. Each runner 







FOUNDATION 


3* 


is successively treated in this manner till the whole 
system has been lowered the necessary amount. It is 
essential that the feet of these runners should be at all 
times kept in the ground, as, if any portion of the 
vertical side of the excavation be exposed, the earth 
is liable to ooze out and leave the back of the runners 
unsupported and cause the whole system to collapse. 

Sinking Shafts.—It is often necessary to sink shafts 
for foundations, etc. These are made from 4 ft. square 
and upwards, the former being the smallest size a man 
can work in without difficulty. 

Shafts from 4 to 9 ft. square are timbered as shown 
in Fig. 19. 

In ordinary soils the earth is excavated to a depth 
of at least 3 ft., and in firm soils 6 ft. The sides of 
the excavation are then lined with vertical sheeting, 
consisting of boards 9 in. wide, 
1 to 1 y 2 in. thick, strutted apart 
by frames of horizontal waling 
timbers, a pair of which is placed 
in position against two opposite 
sides, and strutted apart by another 
pair driven tightly between and 
against the remaining sides, these 
being secured by cleats nailed to 
the fixed waling pieces. Another 
depth of earth is then taken out and a second system 
of sheeting placed in, the upper ends of which lap 
about 1 ft. over the lower ends of the first system of 
sheeting; another frame is placed in position as be¬ 
fore, securing both systems of sheeting. Uprights are 
fixed in the angles between the waling pieces, and often 
at intermediate positions .along their length. This 
process is repeated till the required depth is obtained. 











32 


BRICKLAYERS’ GUIDE 


The timbering requires to be supported if the depth 
be great, to prevent it from sliding down on the 
removal of the earth from its lower end. Where this 
has to be done, the upper end of the shaft is left 
projecting about 3 ft. above the ground level. The 
two first fixed waling timbers at the ground level are 
continued through the shaft, and project several feet 
on either side, a good bearing on the solid ground on 
both sides of the shaft being thus obtained, as shown 
in Figs. 20 and 20A. 



itiese members are usually out of square timbers; tney 
are strutted apart as described. An upright vertical 
timber is notched over this, and spiked to the face of 
the waling timbers below, the whole being thus tied 
together. 

These are often supplemented by similar timbers at 
the bottom of the shaft. These timbers are fixed in 
two pieces, with a scarf in the center; they project 
about 3 ft. into both sides of the pit. A chain is 































FOUNDATION 


33 


sometimes employed in addition to the timber spiked 
to the walings. 

Intermediate struts are required to support the 
horizontal walings where the size of the pit is above 9 



ft. square. One system of struts is fixed between two 
opposite sides, being supported at their ends by cleats, 
as shown in Figs. 21 and 23; these being necessary to 
prevent the timbers falling should they become loose 




during the progress of the work. The struts that 
support the remaining sides intersect by butting, as 
shown in Fig. 22, against the first system, and are 
therefore fixed in two pieces. The struts at their 






































34 


BRICKLAYERS’ GUIDE 


intersection are supported by uprights, on the upper 
ends of which short ends of timber are placed, project¬ 
ing beyond the sides, acting as corbels, and forming a 
ledge upon which the shorter struts take a bearing. 

The earth is raised from the bottom of the shaft, if 
of a great depth, by means of hoisting tackle; but if 
the cutting be shallow, stages are often erected in 6 ft. 
heights, the earth being shoveled from one to the 
other till the top is reached. 

Tunneling.—In building operations it is often neces¬ 
sary to bore a tunnel in order to construct drains* etc., 
,he process being carried out as follows: 

Tunnels are made just large enough for a man to 
«*vi>rk in, that is, from 4 to 7 ft. square. The earth is 
taken out in sections of about 3 ft. at a time, poling 
boards of the same length being then placed against the 
upper surface, and kept in their position by a system 
of strutting, consisting of a head, sill and two up¬ 
rights, out of either round or square timbers. The sill 
is placed in position first, being partly bedded in ground 
to prevent lateral motion, and being bedded in its 
correct vertical position by boning through from the 
sills previously bedded; the head next, then the struts, 
which are cut and driven tightly between the two. 
The next section is then cleared out, commencing at 
the top, just enough being taken out there to allow of 
the next system of poling boards being inserted, these 
being arranged to overlap the first system at their back 
end, the two being then strutted up together; this 
process is repeated till the tunnel is finished. 

If the soil be bad and the sides liable to fall in, they 
must also be lined by poling boards, these being kept 
in their place by the uprights. 

Large spikes, similar in shape to floor brads, are 


FOUNDATION 


35 


driven into the head and sill, with their heads left 
projecting so as to be easily withdrawn, to secure the 
struts when in position. Wood cleats are often used 
in place of these. 

These tunnels are usually made slightly tapering 
from the base to the head, as shown in Figs. 24 and 25. 



Foundations.—The construction of foundations varies 
with the nature and bearing strength of the soil. The 
following are the ordinary soils met with in practice 
and the method of treating them: Rock, chalk, 
gravel, clay and sand. 

Rock.—Foundations laid upon the solid rock are 
undoubtedly secure, as far as settlement is concerned; 
such a substratum being practically incompressible. 
Rocks often have fissures and defective parts, and all 
gaps must be filled up with concrete, any unsound 
parts being cut away. Rock foundations are very 
expensive in working, owing to the extra labor 
involved in cutting them; but where they occur they 
may be built upon direct. 

Chalk.—The sites for buildings on chalk or marl soil 
should be drained, and precautions taken to prevent 

































36 


BRICKLAYERS’ GUIDE 


them becoming wet. Where this can be done, the 
structure can be built upon the chalk or marl direct, 
after it has been leveled; but where heavy buildings 
are erected, or great weights concentrated, concrete 
should be employed to distribute the pressure. 

Gravel.—Where lateral movement is not likely to 
occur, gravel is one of the best soils to build upon; it 
is not affected by the action of the atmosphere, and is 
practically incompressible. 

Clay.—Clay is a good soil to build upon where the 
foundations are taken deep enough to be beyond the 
action of the atmosphere. Clay is very subject to 
expansion and contraction with the variations in tem¬ 
perature, and is therefore dangerous to build upon 
unless protected. 

Sand.—Sand is a good material to build upon, if it 
can be kept dry and confined laterally; if subjected to 
the effects of running water it is liable to be scoured 
from about the foundation. 

In all the above soils, with the exception of the 
rock, and the chalk when in a good condition, it is 
usual to form a bed of concrete, the area of which is 
proportioned to the weight to be carried and the bear¬ 
ing strength of the soil. 

The following are cases that require special treat¬ 
ment: (i) Soft soils of a great depth; (2) soft soils 
with hard strata beneath; (3) soils not having a uniform 
resistance, formed of rocks which have hollows or 
fissures filled up with some softer material. As this 
work is intended to be more of an elementary and 
practical work than otherwise, the foregoing will be 
quite sufficient on the preparation of trenches, cut¬ 
tings and excavations for foundations, at least for the 
present. 


FOUNDATION 


37 


In preparing footings on which to lay bricks, care 
must be taken to keep the work in line and fairly level 
on top before the brickwork is commenced, whether 
the lower footings be of stone or of concrete. At this 
writing, concrete seems to be the popular material in 
use for the lowest layer of foundation, and justly so, 
as, when properly put in place, and the proportions of 
the various materials wisely assigned and mixed, the 
work will be as though one solid stone was laid all 
round the building on which the brickwork may be 
placed. An illustration of the proper method of lay¬ 
ing in a concrete footing is shown in Fig. 26, and one 
that has been adopted in many an architect’s office 
and many a municipal building department. Taking 

the wall in section and ex¬ 
tending the concrete each 
side of the bottom course 
of footings, drop perpen¬ 
dicular lines as outside 
width of concrete, the 
depth being determined 
by an angle of 45 degrees, 
passing from the point A 
of the next work, and cut¬ 
ting the outside line of concrete. A cubic yard of con¬ 
crete would require 27 cu. ft. of broken brick, stone or 
shingle, 9 cu. ft. of sand, 4^ cu. ft. or 3^ bu. of Port¬ 
land cement, and 25 gal. of water. These quantities 
should be correctly measured, turned over together 
three times dry, and again several times while the 
water, through a hose, is being sprinkled over the 
mass. Broken brick or stone small enough to pass 
through i^-in. mesh is preferable for the aggregate. 
The practice of throwing in concrete from a height, in 



Fig. 26. 







38 


BRICKLAYERS’ GUIDE 


order to consolidate the mass—which used to be con¬ 
sidered essential, even when staking had to be erected 
and the stuff wheeled up to the required height at con¬ 
siderable expense—has now exploded. It shouid be 
brought on to the side, deposited and lightly punned 
or beaten down with wooden rammers, but only just 
sufficient to bring the moisture to the surface; if 
rammed too much the cement comes up with the 
water. If, however, it is more convenient to tip the 
concrete into an excavation, no sensible injury will be 
done to it. 

The objection that, in falling, the heavier particles 
separate from the finer is, from the very stickiness of 
the mass, more theoretical than practical, and, at the 
most, applicable only to each separate barrow load 
tipped in, and not to the whole bed. Sliding it down 
a wooden shoot, however, should never be permitted, 
as the cement and small stuff cling to the sides and 
run down in a muddy slush; >vhilst the stones are shot 
out into a separate heap by themselves. 

In ordinary foundations the concrete should be 
deposited in horizontal layers, about 2 ft. thick, and 

care should be taken -1- 

to cover any joints in -1 _LZ 

one layer by the sue- i ' \ 

ceeding one, as the — | * j 

joint between two — -j 1 j — 

days’ work is always I I 1 

a weak part; more- l \~ 1 ~~ i ) 

over, the last layer 


should be well wetted 
to insure a proper 
connection with the 
next. 



Fig. 27. 


















Sections of Footings and Walls in English Bond. 


TT,1 11 1 


w 


~ L ri i i 


7T~TZp= 

■H ' I II II II 


Seof/ons of 

f~oof/ngs and Waits 
in English Bond. 


Sieve fion. 


K Vj) . - 
-X/- 5 h 6 - 


ection N 


rnzi., i 


3 ZH 


i. i i i 




Section of /H Brick 

We// 


TT-T 


P/ofn 


i r~i; 


1 


.' VTTV ', 

— r —r- 1 !—h —\ - 

r r~r f 



Concrete Soc/nda\i/on 


Fig. 28 . 



































































































40 


BRICKLAYERS’ GUIDE 


In Fig. 27 an illustration is shown of a wall and 
footings, the latter being of stone, not less than 6 in. 
thick. On the lower footing of stone is laid another 
course of stonework, and on this is laid the brickwork, 
the top of the upper stone being made level and a 
layer of good mortar spread over it so that the bricks 
have a good bed to rest on. This layer should be 
cement mortar where possible, as it would help to 
make the whole work stronger and better. 

Fig. 28 shows five sections of brick walls and foot¬ 
ings, with the methods of arranging the bricks in the 
wall; there being a one, a one and a half, a two, a two 
and a half, and a three brick wall, showing the pro¬ 
portions for concrete footings. A scale in feet and 
inches is shown on the page, so that the proper meas¬ 
urements may be taken off for actual use. A fact 
worth considering. All these examples are in English 
bond, but are good for any other bond. 

Having dealt with foundations and footings, as we 
hope, in a satisfactory‘manner, it will not be out of 
place to say a few words on damp courses and means 
of preventing damp from getting up into the walls of 
buildings. 

DAMP COURSES 

In the construction of walls for dwellings, or in fact 
any other building of importance, it is essential that 
damp be prevented from being drawn up into the body 
of the wall by attraction; and the first thing to do in 
this case is to give some careful consideration to the 
floors, walls and footings of the cellar. Much has 
been written on the subject, and many recommenda¬ 
tions of more or less value made as to the means of its 
prevention. Whether or not many of these are expe- 


DAMP COURSES 


41 


diencies and not cures, the conditions in each case 
must decide. 

All building materials, with perhaps the exception 
of granite, are porous and capable of absorbing and 
transmitting moisture in large quantity. The damp¬ 
ness in our dwellings, however, arises from a variety 
of causes; from absorption of moisture from the soil in 
or on which the building stands (a clay soil being 
peculiarly bad in this respect); from imperfect joints 
at window sills and lintels, as also unfilled and un¬ 
pointed joints on the face of the wall; from moisture, 
forced into the walls during heavy driving rain storms; 
and from the water used in the process of construc¬ 
tion, in the mortar and plaster, the wetting of brick, 
etc. 

Every damp-preventing device, therefore, should be 
twofold in nature; it should, first, preclude the mois¬ 
ture from getting into the walls, and second, should 
not hinder it from getting out of the walls. The 
former is to be accomplished by an absolutely water¬ 
proof covering, such as asphalt or tar, or the complete 
isolation of the wall from any sources of dampness 
(exception, of course, being made here to the mois¬ 
ture which is put into the walls in building, and which 
should be allowed a proper opportunity to dry out). 
The latter is assured by the perfect ventilation of the 
walls on all sides. 

The remedies for the dampness arising from the sev¬ 
eral causes above noted will be studied in their proper 
relative places. 

There are many devices for keeping moisture from 
entering the cellar walls, and they maybe divided into 
applications to the outside of the wall, and construct¬ 
ive devices. The efficiency of the former depends, in 


42 


BRICKLAYERS’ GUIDE 


large degree, on the care and thoroughness with which 
they are applied. Of this class we have rock asphalt, 
tar and cements. The first and second are applied to 
the wall with a large brush and must, obviously, be 
boiling hot. The coating must be 
not less than three-eighths of an inch 
thick, covering every joint, and be 
carried down to the bottom of the 
footings. To ensure perfect protec- 

_ tion, the wall should have been built 

__- as carefully as possible, the joints 

well pointed, the whole to have be¬ 
come well dried, and the asphalt or 
1 tar applied in two or more coats. 
A The coatings should not stop on the 
Fig. 29. face of the wall, but be carried en¬ 

tirely over the top, Fig. 29. Some 
builders recommend that the asphalt be mixed with 
linseed oil 

Concerning cement as a guard against water, opin¬ 
ions now differ. That it is an excellent protective 
covering when it is well and thoroughly applied is not 
to be questioned. It is, however, frequently fractured 
by the settlement of the walls, and, being to some 
degree porous, suffers from the action of the frost. In 
either case it has no further value as a protective. To 
lay it properly, all the joints and beds of the wall 
should be raked out at least one-half inch deep. The 
coating should not be less than one-half inch thick, 
and should, as far as possible, be applied all at one 
time. If it is necessary to make a joint it should be 
vertical and not horizontal. The last precaution is 
that the earth must not be filled in against it until the 
cement h° thoroughly set. A similar protective 












DAMP COURSES 


43 

covering is made of a concrete of one-half lime mortar 
and one-half good cement (Portland preferred). 

Of constructive devices to guard against dampness 
we have, first, those that are in the wall itself, and 
comprise the horizontal damp courses, hollow brick 
lining and facing and hollow wall. 

The horizontal damp courses are of several kinds, 
and are placed at the bottom of the wall either on top 
of the footings or a short distance above them. The 
most effective course is one of asphalt or tar, Fig. 29, 
applied in coats in the same manner as described for 
the facing of the walls. 

A greater degree of effi¬ 
ciency is given by laying 
the course of bricks imme¬ 
diately above the damp 
course, while the last coat 
is still hot and soft. 

When this damp course 
is set in a stone wall it 
would be better to lay a 
course of bricks and on 
this place the asphalt Fig. 30. 

course, starting the stone¬ 
work above the latter, Fig. 30. A layer of slate, set in 
cement, has been much employed as a damp course. 
It has, however, the disadvantage of being very liable to 
fracture under uneven pressure. Sheet lead is a most 
excellent damp course, and has been applied to the 
purpose for two centuries. For ordinary work its cost 
precludes its use. 

It is claimed that the penetration of moisture can 
be hindered by building the wall so that there are no 
continuous bed joints through the wall. This device 


















44 


BRICKLAYERS’ GUIDE 


is presented on its own merits, the writer having no 
personal knowledge of its efficiency. 

Another excellent damp course is found in the use 
of perforated terra-cotta bricks. These are made the 
same size as the ordinary brick, and can, therefore, be 
readily bended into the wall. A course may be set 
immediately above the footings and another at or near 
the top of the wall. The bricks should be laid so that 
the openings run through the wall and so allow of 
ventilation and evaporation of any moisture that might 



Fig- 3 i. Fig. 32. 


rise in the hollow bricks themselves, as shown in Fig. 
31. The perforated bricks are also used to form a 
vertical damp course. They may be placed either on 
the inside or outside of the wall and may be laid as 
stretchers, as there is not the same liability to collect 
and retain moisture as there is in the horizontal course. 
Headers should be placed at frequent intervals to 
bond the facing to the body of the wall. 

A simple and somewhat inexpensive system of ren¬ 
dering walls absolutely damp-proof and of adding very 
















































DAMP COURSES 


45 


much to their strength and stability is to build the 
brickwork in two 4}£-in. thicknesses with a ^ or ^-in. 
cavity kept clear of mortar. Thin boarding is inserted 
in the cavity as the work advances, the space being 
afterwards filled with rock asphalt compositions. The 
compositions answer the double- purpose of binding 
the two thicknesses together and making the wall 
impervious to moisture. A section of such a wall is 
shown in Fig. 32. 

As a rule damp-proof courses should be 6 in. or 
more above the level of the external ground, but, 

where possible, 
under the wall 
plate carrying the 
joints for the floor. 

In buildings fin¬ 
ished with a para¬ 
pet wall, a damp- 
proof course 
should be inserted 
just above the 
flashing of the gut¬ 
ter, so as to pre¬ 
vent the wet which 
falls upon the top 
of the parapet from 
soaking down into 
the woodwork of the roof a'nd into the walls below. 

In some localities damp-proof courses are formed 
with slates set in cement; these are rather liable to 
crack, and thin impervious stones are better. Sheet 
lead has been used for the same purpose, and is most 
efficacious, but very expensive. 

Arches are frequently rendered all over the extrados 











46 


BRICKLAYERS’ GUIDE 


with asphalt or cement to prevent the penetration of 
wet, same as shown in Figs. 33 or 34. In addition to 
the precaution adopted to prevent damp out of the 
ground from rising in walls, it is necessary (especially 
when using inferior bricks or porous stone) to prevent 
moisture falling upon the outer face from penetrating 
to the interior of the wall. 

The wet may be kept out of the interior of the wall 
by rendering the exterior surface with cement, cover¬ 
ing it with slates fixed on battens or with glazed tiles 
set in cement; 
glazed or enam¬ 
eled facing brick 
answer the same 
purpose. 

Sometimes ver¬ 
tical damp courses 
are used as shown 
in Figs 34 and 35. 
particularly when 
the ground outside 
is higher than the 
wall plate inside, 

“to prevent the 
damp penetrating 
through the wall. 

It will be seen 
that the damp 
course is bedded 
in the wall directly under the wall plate; this prevents 
the damp rising and destroying the wood. The verti¬ 
cal damp course acts in a similar manner in excluding 
the damp through the side of the wall; the joints of 
brickwork should be raked out to receive this damp 






















DAMP COURSES 


47 


course Fig. 35 shows a good method of keeping 
damp out of the main walls. When the ground level 
is higher than floor level it will be seen that a 4%-in. 
wall is carried up to the ground level and covered on' 
top with a stone coping fitted with an iron ventilating 
grating. By this method, as the damp penetrates 
thrdugh the 4j4-in. outer wall, it rises and passes 
through the grating and into the open air. This wall 
is carried about 4)4 in. from the face of main wall, and 

bonded into main 
wall as shown. 
Where the bonds 
enter, the main 
wall is tarred to 
prevent any damp 
entering. 

Another method 
of preventing 
damp from getting 
into a wall is to 
adopt what is 
known as the “dry 
area method,’ 1 
which is simply 
the building of a 
dwarf wall all 
a space of two or 
the walls of the 



Fig. 35 - 


around the building and leaving 
more feet between the dwarf wall and 
building as shown in Fig. 36. It will be seen by sketch 
that the ground is excavated to a width of 2 ft. from 
main walls and the dwarf wall built as shown to keep 
the water away; This area is necessary in damp situ¬ 
ations, as any moisture or wet is carried away by a 
drain that is laid under the area, thus keeping the 






















48 


BRICKLAYERS’ GUIDE 


main structure dry. The dwarf wall is finished with a 
brick-on-edge coping built in cement. The floor of 
area is usually covered with cement concrete paving to 
prevent the water soaking in. Fig. 33 shows an en¬ 
closed dry area formed by means of the arch; this 
area is drained as in Fig. 34, and the moisture is car¬ 
ried through the flue, as shown by dotted lines, into 
the open air. This flue is lined either by neat cement 
or by asphalt to- prevent the moisture penetrating 
into the wall. Hol¬ 
low or cavity walls 
should be used 
for external work 
in damp situations 
exposed to driving 
rains. Such walls 
are of brick or 
stone, with a cav¬ 
ity of 2 or 2)4 in. 

The external wall 
should be 4)4 in., 
the thicker portion 
being inside; false 
headers being used 
in the outer wall. 

The thick wall inside will carry the doors and roofs, 
the woodwork being kept clear of the outer portion, 
which is liable to be damp. 

The cavities should be ventilated by air-bricks in 
the external portion at top and bottom. Care must be 
taken that no mortar or other drippings get into them; 
movable boards or hay bands should be used. 

The wall ties, generally of cast or wrought irori, gal¬ 
vanized orwell tarred and sanded, should be employed 




















DAMP COURSES 


49 


to tie the two walls together; or, better still, a 
tie or bonding brick, which * is made for this pur¬ 
pose, may be used as shown in f'igs. 37 and 38. Walls 
constructed after this method not only exclude the 
damp, but the layer of air they contain, being a non¬ 
conductor of heat, tends to keep the building warm. 
Such walls are formed in two separate portions, stand¬ 



ing vertically parallel to one another, and divided by 
a space of about 2 to 3 in. 

There are several ways of arranging the thickness of 
the portions of the wall, and the consequent position 
of the air space. 

In some cases the two portions are of equal thick¬ 
ness, the air space being in the center, as at Fig. 37. 



































































50 


BRICKLAYERS’ GUIDE 


Very trequently one of the portions is only 4y 2 in. 
thick, built in brickwork in stretching bond; the other 
is of such thickness as maybe necessary to give the 
whole stability, as in Fig. 38. 

In such a case the thin 4^-in. portion is sometimes 
placed on the outside, and sometimes on the inner side 
of the wall. 

In some cases, such for instance as when the wall 
has a stone face, the 454-in. portion is necessarily on 
the inside, but this arrangement has many disadvan¬ 
tages. 

In the first place, the bulk of the wall is still exposed 
to damp, and the moisture soaks in to within 7 or 8 in. 
of the interior of the building. 

Again, if the wall has to carry a roof, expense is 
caused, as the span should be increased so as to bring 
the wall plates on to the outer or substantial part of 
the wall, clear of the 4^-in. lining. 

This may be avoided by bridging over the air space, 
so as to make the wall solid at the top, which, how¬ 
ever, renders it liable to damp in that part. 

On the other hand, if the 454 -in. portion is placed 
outside, the damp is at once intercepted by the air 
space, kept out of the greater portion of the wall, and 
at a considerable distance from the interior of the 
building, and the thicker wall then carries the joists, 
also the whole weight of the roof. 

The following illustrations, Figs. 39, 40, 41, 42, 43 
and 44, show how a hollow wall should be constructed 
in order to have it substantial and effective. Fig. 39 
shows how the angles should be bonded to secure good 
substantial work, also the position of the air-bricks to 
secure good ventilation. Fig. 40 shows how to bond 
the work around fireplace openings, flues and other 


DAMP COURSES 


5i 


similar work. In Fig. 41, sections of a window and 
doorway are shown, also an elevation of brickwork 
with door and doorway in which are shown the posi¬ 
tions of the metal ties marked by the little crosses. 
Fig. 42 shows a plan of the doorway bonded with ties. 
The elevation of wall shown in Fig. 43 illustrates the 
positions of the ties, also of the air-brick. In Fig. 44 
the manner of finishing the top of the wall to take in 



Plans of Bonding at Angles. 

Fig- 39 - 

the wall plate and rafters is shown quite clearly, also 
the position of air-brick. In hollow walls care should 
be taken that the iron ties do not tip inwards, as water 
will in such case traverse even the double twist usually 
employed. The better shape has a V drip in the mid¬ 
dle. To prevent the wet which may enter the air space 
dripping on the window or door frame, a piece of sheet 
lead is built in on the inner side of the 4^-in. exterior 


























































52 


BRICKLAYERS’ GUIDE 


wall, i y 2 in. turned up and carried about 
than the ends of the lintel. 

There is another method sometimes 
because ot its cheapness, and which, in 
proves quite effective 
where the ground is 
dry or composed of 
sand or gravel, and 
that is to lay com¬ 
mon field tiles or 
weeping tiles all 
around the walls 
both inside and out¬ 
side and connect 
them by drain tiles 
to the sewage system 
or to some low spot, 
where the drainage 
will be effective. Fig-. 40. 


2 in. farther 

resorted to 
some cases, 





Fig. 41. 


These weeping tiles should be on a level with the foot¬ 
ings of the building and even lower when possible, to 
get a good fall so that the water will drain off readily* 
It will be understood that the dampness of walls is 
usually owing directly to the absorbent qualities of the 


















































































































DAMP COURSES 


53 


materials of which they are composed and hence 
houses built of inferior bricks, which are always 
absorbent to a considerable extent, cannot be expected 
to be dry, and especially if they are in isolated posi¬ 
tions, where the walls are exposed to the full blast of 
the weather. Even where good materials are em¬ 
ployed, the same effects may be noticed in exposed 
buildings. 

The best construction for a brick building in such 
positions is the employment of the hollow walls, as 
shown in the foregoing, which should be carried up 
throughout the whole of the structure. Their effi¬ 
ciency depends, as in the case of the area walls, upon 



Plan. 

Fig. 42. 


forming a cavity. A damp-proof course should also 
be provided, and may with advantage be made on the 
level of the cavity gutter, so as to answer for the two 
purposes. The few courses of bricks between the 
damp course and the footings may be built solid, the 
bricks being cut to form the necessary width. Various 
ties for connecting the casings are in the market, two 
of which are represented in the illustrations. That 
formed of brick is moulded so as to rise a course front 
to back to prevent the water from creeping along it, 
and the iron tie is provided with a middle indentation 
for the same purpose. 

Properly constructed, these cavity wails are quite 






























54 


BRICKLAYERS’ GUIDE 


effectual in rendering a building dry. They should 
always be employed for buildings standing by them¬ 
selves. Strips of lead, tin, zinc or other metal must 
be placed over all door and window openings, being 
bent so as to throw any water falling upon them into 
the gutter below. Cavity walls cost very little more 
than solid ones. The quantity of bricks used in the 
construction is almost the same, the only extra mate¬ 
rials being the ties and the guttering. Besides keep¬ 
ing the building dry, hollow walls have the advantage 
of rendering the interior of the house less affected by 



Fig. 43 - 


changes in the temperature, rendering it cooler in the 
summer and warmer in the winter, a considerable 
advantage in a variable climate like this. The hollow 
space, moreover, lends itself very readily for the pur¬ 
poses of ventilation. 

Dampness will sometimes be found to arise from the 
soil below the floor, and in building upon such soils 
the whole site should be covered in, beneath the low¬ 
est floor, with dry earth, or, better still, with a thin 
layer of concrete, which will prevent the damp rising 
from that source. 





























DAMP COURSES 


55 


Referring now to the cure of damp buildings, it will 
nearly always be found to be at the best a troublesome 
matter. Sometimes the building will have been 
erected without a damp course, and the insertion of 
one by underpinning all around the building will, in 
such cases, generally effect a cure; or it may penetrate 
through the walls, either in the case of a cellar wall, 
from the earth resting against it, or from the rain beat¬ 
ing through in the stories above. In the first case it 
may be removed by digging away the soil around the 
building and erecting a dry area wall, such as that 
before referred to, but as this is always quite an expen¬ 
sive way a simpler method may be tried. See that the 
earth around the building is properly graded, construct 
small air shafts at frequent intervals, inserting air¬ 
bricks above the ground line so as to place the space 
beneath the floor in direct communication with the 
outer air. This may be sufficient of itself, but if the 
wall is plastered and still shows signs of dampness, 
proceed as follows: 

Hack off all the plaster from floor to ceiling. Place 
a stove in the middle of the room and keep up a large 
fire, night and day, until the walls feel quite dry to the 
hand. Then render the walls in plaster composed of 
nearly neat Portland cement. 

Many obstinate cases have been cured in this man¬ 
ner. Re-rendering the plaster is expensive, and various 
paints and washes are in the market for application to 
the face of the plaster to keep out the damp. Some 
of them are effective, but the success of all depends 
upon the very simple precaution of stripping the whole 
of the paper from the walls and getting them dry 
before applying the wash or paint. In some cases the 
dampness will be found to rise some 2 ft. only from 


BRICKLAYERS’ GUIDE 


56 

the ground, and a cure has been attempted by painting 
the wall or applying lead foil beneath the paper to 
that height; but the method is useless, for the damp 
will only rise and show itself above the line of foil or 
paint. 

In outside walls dampness will sometimes show itself 
in small patches here and there, and sometimes in 
quite large patches. The small patches probably arise 
from a few bricks of inferior quality which have inad¬ 
vertently been built in the wal 1 , and a cure can gener¬ 
ally be brought about by covering the space on the 
inside of the wall beneath the paper with lead foil, 
using it to cover a space about 6 in. beyond the actual 
space of dampness. Where large spaces on the wall 
show damp, it may arise from defective gutters, from 
bad bricks, want of pointing, or other causes. Remove 
the cause, if possible, and if that cannot be done, the 
following remedy will prove of use. Melt 3 lbs. of 
strong soap in 4 gal. of water, and carefully apply to 
the wall, so as not to produce a lather. Mix lb. of 
alum with 4 gal. of water, allow it to stand for 24 hrs. 
(by which time the soap will be in a condition to 
receive it), and carefully apply as before. 

The following is said to be quite effective in keeping 
out damp, when properly applied to outside walls: 
Soft paraffin wax, 2 lbs.; shellac, lb.; powdered 
resin, y 2 lb.; benzoline spirit, 2 qts.; dissolve these 
by gentle heat in a water bath, then add 1 gal. of ben¬ 
zoline spirits and apply warm. The mixture is very 
inflammable, and must be kept away from the fire. 
We may mention here another method of making 
brickwork impervious to water, known as Sylvester’s 
process, which was used with success on the Croton 
reservoir, Central Park, New York. It consists in the 


DAMP COURSES 


57 


successive application to the walls of two washes, one 
composed of Castile soap and water, and the other of 
alum and water. The proportions are ^ lb. of soap 
to i gal. of water,' and y 2 lb. of alum to 4 gal. of 
water. The walls should be quite dry and clean, and 
the temperature of air not below 50 degrees Fahr. 
The soap wash is laid on first with a flat brush and at a 
boiling heat. After 24 hrs. the wash becomes dry and 
hard, and the alum wash is applied at a temperature of 

60 to 70 degrees Fahr. 
This is allowed to re¬ 
main 24 hrs., when the 
operation is repeated 
until the wall has be¬ 
come impervious to 
water. The number of 
applications required 
will depend on the 
water pressure to which 
the wall is subjected. 

In the Croton reser¬ 
voir cases, four coatings were found to render the 
reservoir free from leakage under 40 ft. head. This 
is similar to the recipe given in another paragraph. 
Resin has been used also as a protection against mois¬ 
ture. Five parts of turpentine, heated and stirred in 
ten parts of pulverized common glue, and one part of 
finely-sifted sawdust are then applied to the wall, which 
should be cleansed and heated by means of a lamp, 
so that the composition may run into every crack and 
joint. Very often a cement lining is of no use to 
make a tank water-tight, especially where the bricks 
and joints are of an inferior description, and the aim 
should be to get a composition which, when heated, 





















58 


BRICKLAYERS’ GUIDE 


enters the pores of the brickwork and renders them 
impervious. 

The top of a wall also may be as likely to admit 
dampness as the bottom or sides, if it is not properly 
protected by the roof or by proper copings; as the 
rain, sleet and snow are liable to soak down into the 
body of the brickwork and cause damp and decay. 

Copings maybe of a variety of shapes and materials, 
stone, copper or other sheet metal, terra-cotta tiles, 
brick or cements. If bricks are employed, good Port¬ 
land cement mortar should be plastered over it, cover¬ 



ing it at least an inch deep. A number of copings are 
shown in Fig. 45. The first illustration shows a wall 
covered with a half-round pressed brick laid in cement 
mortar. The other illustrations show for themselves. 

There will often occur cases where it will be expe¬ 
dient to support loads by the method of brick corbel¬ 
ing, which consists of one or more courses projecting 
the required distance from the wall. 

There are two points that have to be considered in 
corbeling. The first is, that as every projecting brick 
is acting as a cantilever the end of the brick should be 













BRICK CORNICES 


59 


tailed into the wall as far as possible. To obtain this, 
as many headers as are available are used. Secondly, 
the projection of every course over the one below should 
not exceed in.; but it is better if it is only in. 
Corbeling renders the walls less stable by bringing the 
center of gravity of the mass nearer the internal edge 
of the wall. Figs. 46 and 47 give two examples. 



Fig. 46. Fig. 47. 

BRICK CORNICES 


Brick cornices are carried out on the principles of 
corbeling, the length of bricks being 9 in. No cornice 
made entirely of bricks should project more than that 
amount. This being accepted, bricks are more suit¬ 
able for the large projecting cornices of buildings 
treated in the classic styles. Wherever bricks are 
employed in the latter styles, if the cornice has 
modillions, the latter are usually of stone of a color 
resembling the bricks and well tailed into the wall, 
thus forming a support for the crowning courses, as 
shown in Fig. 48. Fig. 49 shows the brick backing 
for a plastered cornice; the large projection is also 
here obtained by the use of stone. Bricks are more 
suitable for cornices of buildings of the Gothic styles, 
























6o 


BRICKLAYERS’ GUIDE 








































BRICK CORNICES 


61 


which usually resolve themselves into a moulded band 
supported by a corbel table, as shown in Figs. 50 to 
54. In either variety there is no detriment in placing 
the bricks on edge wherever the dimensions of the 
members or disposition of the arts render that arrange¬ 
ment necessary. 

Another style of cornice, in which moulded bricks 
are used, is shown in Figs. 55 and 56. In setting this 
out, convenient lengths should be taken, e.g., from 



Fig, 55 - 


and including pilaster and pilaster, and the whole, or 
in the case of a long length, the half, or even quarter, 
should be laid out upon plan, breaking round project¬ 
ing keys, etc., the setting out pricked over for headers 
and stretchers, or, if the projection be too great, then 
for headers only, so as to get an exact number without 
broken bond. It may occur that the headers and 
stretchers are slightly over or under 4^4 and 9 in.; but, 
whatever the size, a gauge is cut to it, and the headers 
and stretchers reduced to the gauge. The bricks 

























































































62 


BRICKLAYERS’ GUIDE 


should be joggled, and the work properly run in with 
Portland cement. All internal miters, stopped returns, 
etc., in cornices should be solid. Some brick cutters 
make cut miters, putting them together dry, as being 
an easier method; but this is not correct work. 

It will be noticed in Fig. 55 that the cornice is con¬ 
tinued round, and forms a cap to the pilaster; the prin¬ 
cipal perpends in the plain work of this and of the 
general face work being continued through the cornice 
as far as possible. The breaking out of the returns 



Fig. 56 . 


round the pilaster and the bonding between the latter 
and the straight run of cornice is made out where 
necessary in between. Thus taking course I of the 
cornice in elevation, Fig. 55, the brick A pairs with 
the plain brick B, which goes home to the pilaster. 
If A did the same, then a joint would occur imme¬ 
diately over the angle of the pilaster, and the return 
would appear as if it were merely stuck on, which 
would be unsightly; hence, to remove the joint from 
this point, A becomes a bat header, and a solid return 
is obtained in the three-quarter bat C, which, on 
account of projection, as will be seen upon plan, is 
made out by a brick shellacked to the back of it. As 
already stated, it is sometimes necessary for headers 
only to be used in cornices. This applies with greater 
force to the top course, where they are frequently 























BRICK CORNICES 


63 


beveled to form a weathering. The bonding of the 
courses 1, 2, 3 and 4 upon elevation agrees with those 
marked 1, 2, 3 and 4 upon plan. (See Fig. 56.) 

In making plain pilasters and cutting and setting 
them out, but little more skill is required than that of 
gauging bricks for a Gothic arch, 
unless they be fluted or seeded, or 
both; then a pair of moulds cut to 
the plan of the pilaster should be 
used; the brick being worked in the 
box face upwards, the back of the 
brick on the bottom of the box being 
roughly squared. The difficulty lies in setting out the 
proper bonding of the base and cap. The full-size 
plan and elevation of each should be worked in con¬ 
junction with a few courses of the plain work; the 
bond accurately set out, and the work cut according 





~m - ’ 







3 





J. 


2 1 



L 






f - 

1 





1 























Fig. 58. 


to it (see Figs. 58 and 59, which represent the eleva¬ 
tion and plan respectively of the base). Here it will 
be noticed that the bonding of the plain work of the 
pilaster and also the general face work is kept as far as 
possible, courses 1, 2, 3 of the elevation agreeing with 
1, 2, 3 of the plan. The cap of the pilaster is taken 
in conjunction with cornices. 

Pilasters vary in shape upon plan, and the correct 




















































64 


BRICKLAYERS’ GUIDE 


bonding must be dealt with as the cases occur; but an 
instance is given in Figs. 60 and 61 of a half-octagonal 
pilaster, and in Figs. 62 and 63 of a half-hexagonal. 

It frequently happens that the bricklayer has to 
panel a wall under windows, in gables and other 
similar places, and in order that the workman may be 



Fig. 59- Fig. 6o - 


prepared for such work the following has been selected 
which gives a few instructions on the subject, and which 
will be found simple and easy to follow: 

In setting out panels, the height is usually kept in 
courses with the general work; but the width is not 
always the multiple of a 9-in. stretcher, and needs 
consideration. Set up a quarter of the panel, what- 



Fig. 61. Fig. 62. Fig. 63. 


ever the width, including the moulding, and prick 
over for headers and stretchers. Let Fig. 64 be a 
quarter of a panel, measuring 4 ft. in width. Had the 
width been 3 ft. 9 in., it is very clear that five 9-in. 
stretchers would exactly fill it; but, as it is 3 in. over 
this, divide the 3 in. equally among the five stretchers, 
making them slightly over 9 in., and the headers and 
closers in proportion. The joints will be arranged as 
in Fig. 64; the mould for the side stretchers, e.g., 


























BRICK CORNICES 


65 


A B, etc., will be as in Fig. 65, one side of the brick 
being roughly squared and placed on the bed of the 
box; thus the brick will be worked on edge with the 
moulding upwards; the moulds for the top and bot¬ 
tom horizontal moulding being as in Fig. 66, and 



worked with the roughly squared bed of the brick on 
the bottom of the box, the moulding again being 
upwards. The side headers C D, etc., will require 
another pair of moulds (Fig. 67), the brick being 
placed in the box on edge and moulded on the end. 

_ 

Mould, for side 
stretchers. 

Fig. 65. 


Mould for top and 
bottom courses. 


Fig. 66. 


All angles should be cut in the solid brick, with no 
mortar joint. 

A projecting key is sometimes adopted in an arch 
as an ornamental feature, when some few of the center 
bricks, including the key-brick and those adjacent, are 
made to stand out from the general face of the arch; 






























































66 


BRICKLAYERS’ GUIDE 


sometimes being also moulded (Fig. 68). Whatever 
size the block may be at the top, it is divided into odd 
courses; thus 8 in., in., etc., would make three 
courses, 14 in. five courses, etc., the course being cut 
to the same template as those for the rest of the arch, 
though, if necessary, to a different 
cutting mark. If the projecting 
key is also to be moulded on the 
face, as Fig. 68, the bricks are first 
cut to the template, the depth and 
thickness being properly arranged 
and bonded (Fig. 68 and 69, which 
show one course in definite and the other in dotted 
lines), then set, or “blocked” as it is practically 
known, together with white lead and shellac, and after- 


Mould for side 
headers. 


Fig. 67. 



Fig. 68. 


Fig. 69. 


wards cut in the box, face upwards, in the same way 
as ordinary mouldings. 

There are many other difficult and interesting details 
in ornamental brickwork, which it is hoped will be 
treated upon in some future work. 
























BONDING 


67 


BONDING 

The question of “bond” is one of the most impor¬ 
tant in brickwork, yet few bricklayers give much atten¬ 
tion to this department of this work. They generally 
follow certain rules customary in the locality in which 
they reside, or methods they learned during their 
apprenticeship. 

Bond (that is, to bind) is the name given to any 
arrangement of bricks in which no vertical joint of one 
course is exactly over the one in the next course 
above or below it, and having the greatest possible 
amount of lap. 

Bond in brickwork is the method of arranging each 
brick so that it laps over the bricks with which it is in 
contact above and below a distance equal to one- 
quarter of the length of the brick. To ensure good 
bond the following rules should be rigidly adhered to: 
First, the arrangement of the bricks must be uniform, 
and as few bats as possible be employed; second, a 
closer to be inserted after the quoin header in any 
course; third, the vertical joints in every other 
course to be perpendicularly in line on the internal as 
well as the external face; fourth, stretchers are only 
to be used on the faces of the wall, the interior to 
consist of headers only, except in footings and corbels; 
fifth, the dimensions of bricks should be such that, 
when bedded, the length should equal twice the width 
plus a mortar joint. 

Hindrances to good bond often occur when facing 
or pressed bricks used are costly or of different 
lengths and widths to the body of the wall; in 9-in. 
walls, where it is necessary to have two fair faces, very 
frequently facing both on the outside and inside. 


68 


BRICKLAYERS’ GUIDE 


English Boncf , 

I I l.i-Lj- ijir 

T Stretcher I I 


u r ;i u : 

ii j. r~T | ji: 


Elevation of Wall 
Fig. 6gk 


Quo\n 


Fig. 70. 


0 jeen closer 


Fig. 71. 


Fig. 72. 


Sfothe d 

End. 




Fig,. 76. 





Broken bond near 
re of waller opening 





1 

j eenf\ 































Fig. 77. 


I 



Fig- 75 - Fig. 79. 

Figs. 69-79. Examples of English Bond. 


























































































































































































































BONDING 


$ 

There are several kinds of bond used in brickwoik v 
among which we may name: first, English; second, 
double Flemish; third, single Flemish; fourth, Eng¬ 
lish cross; fifth, Dutch; sixth, stretching or chimney; 
seventh, heading bond; eighth, country or garden- 
wall bond; ninth, raking bonds; tenth, hoop-iron 
bond. When the bond is arranged as shown in eleva¬ 
tion and plan Figs. to 79, it is known as English 
bond, and sometimes old English bond. It consists 
of one course of headers and one course of stretchers 
alternately. In this bond, bricks are laid as stretchers 
only on the boundaries, of course, thus showing on the 
face of the wall, and no attempt should be made to 
break the joints in a course running through from 
back to front of a wall. That course which consists of 
stretchers on the face is known as a stretching course, 
and all in course above or below it would be headers 
with the exception of the closer brick, which is always 
placed next to the quoin header to complete the bond, 
and these courses would be called heading courses. 

It may be noticed that in walls, the thickness of 
which is a multiple of a whole brick, the same course 
will show either: 

(a) Stretchers in front elevation and stretchers in 
back elevation. 

(b) Headers in front elevation and headers in back 
elevation; but in walls in which the thickness is an 
odd number of half bricks the same course will show 
either: 

(a) Stretcher in front elevation and header in back 
elevation. 

(b) Header in front elevation and stretcher in back 
elevation. 

In setting out the plan of a course to any width, 


BRICKLAYERS' GUIDE 


Double Flemish Bond. 



[ 

L 

Fig. 83. 























Fig. 84. 


I 

I 


L . 

Fig. 86. 


























Fig. 88. 

































1 

| 



Fig. 89 




, 

1 












1 








-1- 

— 



- 1 - 








1 

j 

Fig. 90. 

1 














































Fig. 80-90. Examples of Double Flemish Bond. 



















































































































































































































































































BONDING 


7J 


draw the quoin or corner brick; then next to the face 
(which in front elevation shows headers) place closers 
to the required thickness of the wall, after which set 
out all the front headers, and if the thickness is a 
multiple of a whole brick, set out headers in rear; the 
intervening space, if any, is always filled in with 
headers. 

Double Flemish bond has headers and stretchers 
alternately in the same course, both in front and back 
elevations, as shown in Figs. 80 to 90. It is weaker 
than English bond, owing to the greater number of 
bats and stretchers, but is considered by some to look 
better on the face. It is also economical, as it admits 
of a greater number of bats being used, so that any 
bricks broken in transit may be utilized. By using 
double Flemish bond for walls one brick in thickness, 
it is easier to obtain a fair face on both sides than with 
English bond. 

Single Flemish bond consists in arranging the bricks 
as Flemish bond on the face, and English bond as 
backing. This is often done on the presumption that 
the strength of the English bond as well as the external 
appearance of the double Flemish is attained, but this 
is questionable. It is generally used where more 
expensive bricks are specified for facing. The thin¬ 
nest wall where this method can be introduced is 1 y 2 
brick thick. Plans of alternate courses are given 
(Figs. 91 to 99). The front elevations are the same as 
in double Flemish bond. 

English Cross Bond. —A class of English bond. 
Every other stretching course has a header placed 
next the quoin stretcher, and the heading course has 
closers placed in the usual manner (Fig. 100). 

Dutch Bond. —In every alternate stretching course a 


72 


BRICKLAYERS’ GUIDE 


Fig. 91. 

Single Flemish Bond. 



Elevation of Wall 





Fig. 92. 













?<✓ 

- 5 *- 





S 

to pin 


r~y >— L 

Uuo/n 




L 


Fig. 94. 














zzz 

- 1 — 








1 



1 



Fig. 96. 













in 






















Fig. 97 . 




Figs. 91-99. Examples of Single Flemish Bond. 































































































































































































































BONDING 


7 3 


neader is introduced as the second brick from the 
quoin; three-quarter bricks are used in the remaining 
stretching courses at the quoins, and the closers are 
dispensed with in the heading courses, as shown in 
Figs, ioi to 105; the longitudinal tie becomes much 
greater, and the appearance of the elevation is cer¬ 
tainly superior to much of the inferior work one is 
accustomed to see as examples of the modern brick¬ 
layer’s skill in bonding. Should there be a fracture, it 
is supposed to throw it more obliquely. 

Stretching bond should be used only for walls half 
brick thick, as for partition walls. All bricks are laid 
as stretchers upon the face. 

Garden or boundary-wall bond, country bond, Scotch 
bond, are the names given to walls built with three 
stretchers and one header in same course, constantly 
recurring, as shown in elevation, Fig. 106. This 
method is used for walls one brick thick that are seen 
on both sides, as it is easier to adjust the back face by 
decreasing the number of headers, the lengths of which 
usually vary. 

Heading bond is used when circular corners have to 
be turned, as in Figs. 108 and 109. It is evident that 
stretchers, unless it be upon a large curve, would be 
too long for this purpose. 

In walls built of material in which it is impossible to 
get a bond, two or three courses of brickwork are fre¬ 
quently introduced to act as a tie or bond; these are. 
termed lacing courses. Again, in big arches, consisting 
of 4^-in. brick wings, lacing courses are sometimes 
used to give additional strength, as in Fig. no. 

Hoop-iron Bond. —An additional longitudinal tie 
termed “hoop-iron bond” is often inserted in walls, 
being usually pieces of hoop-iron I in. x ^ in., one 


Fig. 100. 


Dc/fch 



3one/ 

-U i _L J II t , f ■ t 


Fig. i of. 




rim 




n ^ r r ri i " i " i | L 


E/evof/on on Return E/evof/on 







Figs. 100-107. 












































































































































BONDING 


75 


row for every half brick in the thickness; should be 
carefully tarred and sanded or galvanized before 
using, to prevent oxidation. It is hooked at all angles 
and junctions. If bedded in two courses in cement, 
additional strength is gained; pieces of hoop-iron may 
be used with advantage where the bond at any part of 
the wall is defective. 

Raking Bonds. —Walls as they increase in thickness 
increase in transverse strength, but become proportion¬ 


ally weaker in a 
longitudinal direc¬ 
tion, owing to the 
fact that stretchers 
are not placed in the 
interior of a wall. 



Fig. 108. 


This defect is remedied by using raking courses at 
regular intervals of from four to eight courses in the 
height of a wall. The joints of bricks laid in this 
position cannot coincide with the joints of the ordinary 
course directly above or below, the inclination of the 



Fig. 109. 


Fig, no. 


face usually being determined by making the extremi¬ 
ties of the diagonal of two, three or more bricks coin¬ 
cide with the backs of the facing bricks. It is not 
advisable to use one raking course directly above 
another, as there is always a weakness with the face 
bricks at the junction of the raking. 

Raking bonds are always placed in the stretching 












76 


BRICKLAYERS’ GUIDE 


courses in walls of an even number of half bricks in 
thickness, in order that their influence may extend 
over a greater area than would be the case if they 
were placed in the heading courses. 

The alternate courses of raking bonds should be laid 
in different directions, 
in order to make the tie 
as perfect as possible. 

There are two varie¬ 
ties of raking bonds, 
viz., diagonal and her¬ 
ring-bone. 

Diagonal Bond. —This 
is used in the thinner 
walls, i. e., between two 
and four bricks in thickness. The operation is as 
follows: The face bricks are laid; one or more bricks 
(in the latter case placed end to end) are bedded 
between the face bricks, so that the opposite corners 

touch the latter; this 
determines the angle 
that the bricks should 
be laid, the triangular 
spaces at the ends of 
the bricks being filled 
up with small pieces of 
brick cut to shape, as 
shown in Fig. in. 
Herring-Bone Bond.— 
The bricks in this method are laid at an angle of 45 
degrees, commencing at the center line and working 
towards the face bricks. Herring-bone bond is used 
for walls four bricks and upwards in thickness. Fig. 112 
shows this method. 







'■//// 

vXXX\ 






Fig. 112. 




B 


A 

\ \ / \ \ I 

A A/ A 1 

C X x \ V 

\ /\ \ \ 1 

\ / \ \ \ 1 

// \ / \ / \ 1 




fl 


Fig. hi. 
































BONDING 


77 



Figs. 113-120 Junctions of Cross Walls. 
























































































































































?8 


BRICKLAYERS’ GUIDE 


Diagonal and herring-bone patterns are often used 
to form ornamental panels in the face of walls, and 
also in floors paved with bricks. 

Junction of Cross Walls.—The bond is obtained in 
cross or party walls abutting against main walls by plac¬ 
ing a closer 4 y 2 in. from the face in every alternate 
course in the main wall, thus leaving a space 2^ in. 
deep and of a length equal to the thickness of the cross 
wall for the reception of the i^-in. projection in every 
other course of the cross wall, as shown in Figs. 113 
to 118. 

Figs. 119 and 120 illustrate the junction of one-and- 
a-half brick Flemish bond with one brick English bond. 

Reveals.—The vertical sides of window or door open¬ 
ings between the face of wall and window or door 
frames. The horizontal distance between is the clear 
span of opening. 

Jams are the vertical sides of an opening, and in 
rebated window or door openings there are the internal 
jambs and external jambs, the latter being known as 
the reveals. 

Internal jambs are usually covered with plaster, or 
wood linings. 

Figs 121 to 131 show brick reveals, with rebated 
jambs in English bond. 

Splayed Jambs.—The internal jambs of windows 
occurring in thick walls are often splayed to obstruct 
as little light as possible. Figs. 132 to 142 show the 
method of bonding two alternate courses of a three- 
brick wall, built in single Flemish bond. In inferior 
work splayed jambs are often formed by simply con¬ 
structing a number of square offsets. 

Squint Quoins.— External angles other than a right 
angle in plan are called squint quoins. Such require 


BONDING 


79 


Fig. 121. 


Fig. 122. 


Fig. 126. 


Br/cU Beves)/s yv/fh reh&fed 
□ j&mbs /n English Bond. 
Fig. 123. 











Fig. 125. 

L 











Fig. 124 





Figs. 121-131. Brick Reveals with rebated jambs in English Bond. 














































































































































8o 


BRICKLAYERS’ GUIDE 


considerable care in the planning, as different angles 
require special modifications of the principles of 
bonding. 

Two general rules should be kept in view, viz.: (i) 
no bird’s mouth joint in plan should be employed, 
except on the face of the work in acute angular quoins, 
where it is at times absolutely necessary. They would 
be useful in the interior in some cases, but sufficient 
care is not usually taken in cutting the re-entering 
angle where the brick is not exposed to view, the 
latter generally becoming cracked or broken, as bricks 
dc not lend themselves to be easily cut in this manner. 
(2) All small pieces should be avoided, the bricks being 
as nearly as possible whole, and only having sufficient 
cut off to adapt them to the plan. Closers are not 
always necessary in obtuse angles; better work is pro¬ 
duced where they can be superseded. It is evident 
that the quoin stretcher can never show its full length 
on either face. Advantage should therefore be taken, 
if the angle is not too great, to show three-quarters of 
a brick at the quoin, as shown in Figs. 137 and 138, 
thus obviating the necessity of a closer to gain the 
proper 2^-in. bond; but in acute angles, the quoin 
stretcher can always be obtained in its full length, as 
shown in Figs. 139 and 140. 

Figs. 132 to 136 show the method of constructing 
squint piers, such as would be employed in the angles 
of bay windows. 

Toothing.—The usual method of leaving a brick wall 
which is to be continued at some future time is to 
tooth it, which consists in leaving each header project¬ 
ing 2% in. beyond the stretching courses above and 
below to allow the new work to be bonded to the old 
as shown in Fig. 144. 


BONDING 


81 


Fi g J 32 Fig. 133. 

P/a/7s 0 / Scjru/nf P/ers Fig. 134. 
1 9 ‘ 

^ 9 ' 





Figs. 132—142. 











































































82 


BRICKLAYERS’ GUIDE 


The usual practice in joining new cross walls to old 
main walls is to cut out a number of rectangular 
recesses in the main walls equal in width to the width 
of the cross wall, three courses in height, and half a 
brick in depth; a space of three courses being left 
between the sinkings (as shown in Fig. 143) I the new 
cross wall is then bonded into the recesses with cement 
mortar to avoid any settlement. It is necessary that 
the sinking should not be less than 9 in. apart, as in 
the cutting the portion between is likely to become 
shaken and cracked. 

Racking.—Racking is the term applied to the method 
of arranging the edge of a brick wall, part of which is 
unavoidably delayed while the remainder is carried up. 
The unfinished edge must not be built vertically or 
simply toothed, but should be set back 2 % in. at each 
course, to reduce the possibility and the unsightliness 
of defects caused by any settlement that may take 
place in the most recently built portion of the wall. 

Also where new walls are erected the usual method 
of procedure is to build what is technically termed a 
corner—that is, the angles or the extremities of the 
walls—to a height of two or three feet, the angle bricks 
being carefully plumbed on both faces. The base of 
the corner is extended along the wall, and is racked 
back as the work is carried up, as shown in Fig. 145. 
The intermediate portion of the wall is then built 
between the two corners, the bricks in the courses 
being kept level and straight by building their upper 
edges to a line strained between the two corners. 

Leveling of Brickwork.—In bedding bricks, great 
care should be taken to keep all courses perfectly 
level To do this, the footings and the starting course 
should be carefully leveled through, using a level at 


BONDING 


Si 


Fig- M3- 


































BRICKLAYERS’ GUIDE 


8<i 

least io ft. in length, commencing at one end and 
leveling towards the other, and taking care to reverse 
the level each time at each forward step, and com¬ 
pleting the length to be leveled in an even number of 
steps. A piece of slate or iron is left projecting from 
the lowest course, and from this all other courses at 
the corners can be leveled by using the gauged rod, 
which is usually about io ft. in length, with the courses 
marked on it. The work should then be again tested 
by the level, and the operation repeated. 

Joints.—Bricks and stones are bedded with mortal 
for two purposes, viz., to cause the bricks to adhere to 
each other, and to distribute the pressure uniformly 
over the whole bed where the beds of the bricks or 
stones are irregular. Great care should be taken that 
both the bed and side joints are thoroughly flushed, or 
filled up with mortar. This is done in three ways: I, 
by the trowel; 2, by larrying; 3, by grouting. The 
first method is that usually adopted in thin walls. The 
second, larrying, is largely adopted in thick walls. 
The face bricks are first laid; the mortar, in a semi¬ 
fluid condition, is then poured into the space between 
the face bricks; the bricks are then pushed rapidly 
horizontally for a short distance into their position; a 
certain amount of the mortar is thus displaced; this 
rises in the side joints, and completely fills all the 
interstices; should the mortar not rise to the top of 
the joints, the vacant spaces are filled up when the 
next course is larried. (3) Grouting is an operation 
used in brickwork, generally for gauged arches and 
similar work, where fine joints are required; it consists 
in mixing the mortar to a fluid condition, of about the 
consistency of cream, this being poured into the joints 
of the work after the latter has been placed in position. 


BONDING 


85 


Joints on Face. —The joints on the face of work are 
finished in a variety of ways, as shown in Figs. 146, 
A to L, to increase the effect, and to resist the weather; 
they may be finished as the work proceeds, or as the 
scaffold is taken down on the completion of the build¬ 
ing; the former is the stronger and more durable, the 
latter is cleaner and has a 
better appearance, and is 
rendered necessary when 
the work has been built 
during frosty weather; 
where the latter method 
is employed, the joints 
should be raked out for 
at least ^ in. in depth as 
the work proceeds. The 
joints in new work should 
be clean, sharp and regu¬ 
lar; but no fancy pointing 
is permissible. Fig. 146, 

A to L, shows the forms 
of joints applied to brick¬ 
work. 

Flat or Flush Joints.— 

This is formed (as shown in Fig. 146, A) as the work 
proceeds by pressing with the trowel the wet mortar 
that protrudes beyond the face, flat and flush with the 
wall. 

Flat Joint Jointed. —This is formed similarly to the 
above (as shown in Fig. 146, B), but has, in addition to 
the previous joint, a semicircular groove run along 
the center of each joint, with a jointing tool and 
straight-edge. This has the effect of making the 
mortar more dense. 



Fig. 146 a to l. 
































86 


BRICKLAYERS’ GUIDE 


Struck Joints.—This is formed by pressing with the 
trowel the mortar along the upper edge of the joint 
slightly below the surface, as shown in Fig. 146, C. 
This is a good joint, as the upper edge of the mortar is 
protected, and any water is thrown off with facility; its 
appearance is good, as it presents a sharp shadow at 
every horizontal joint, and forms the method of finish¬ 
ing new work; it is sometimes called a weather-struck 
joint. The mortar is often ignorantly struck back on 
the lower edge, as shown in Fig. 146, D, under the 
impression that the appearance is enhanced thereby, 
the idea being that a sharp line is presented on the 
upper edge of the bricks, but as no shadow is formed 
the effect is lost at a few feet above the eye; a ledge 
is formed on which the water lodges, which freezes in 
the winter, and rapidly destroys the upper edges of the 
bricks and the joint. 

Keyed Joint, as shown in Fig. 146, E, is formed by 
drawing a pointing tool with a curved edge, the same 
width as the joint, along the latter; it has the effect of 
making the mortar dense at this part, and improves 
the appearance by making the joints distinct. It is 
not much used. 

Keyed joints of the form shown in Figs. 146, G and 
H, are employed where the wall is to be rendered. In 
the first case, the mortar in the joints is left protrud¬ 
ing; in the second, it is raked out. 

Recessed Joint.—This is used to obtain a pleasing 
and deep shadow, but care must be taken that the 
bricks are hard and unlikely to be damaged by the 
weather. It is the joint employed in many of our best 
buildings. Fig. 146, F, gives this joint. 

Pointing Old Works. —This operation consists in rak¬ 
ing out the decayed mortar from the joints to a depth 


BONDING 


87 


of at least ^ in. and in filling the same with cement, 
or some hard-setting mortar, as shown in Fig. 146, I. 
The joints may be finished in any of the methods 
stated, or by one of the two methods known as tuck 
and bastard tuck pointing, which are fancy forms 
adopted by bricklayers to increase the effect by form¬ 
ing sharply defined joints. 

Tuck pointing, as shown in Fig. 146, J, consists in 
filling up the raked-out joints flush with a stopping of 
cement or some hard mortar. The joints in this con¬ 
dition generally appear very wide, owing to the edges 
of the bricks being ragged, this being due to the frost 
or to the clumsy method in which the joints have been 
raked. The whole front, joints included, is then col¬ 
ored with a compound of copperas and a pigment of 
the color required, or the front is rubbed with a piece of 
soft brick till the bricks and the joints are of one color. 
While lime putty is pressed on to the joints in straight 
lines, with a jointer worked on a beveled edge straight¬ 
edge, and before the latter is removed, the edges are 
trimmed with a tool called a Frenchman, which usually 
consists of an ordinary table knife with the end of the 
blade turned up at right angles to the remainder. The 
edge of the knife cuts the putty, and the turned-up end 
drags off the superfluous stuff, leaving a white joint 
^-in. in width and ^Vin. in thickness on the face of 
the work. This is not the best method of pointing 
if the bricks are sound and their edges sharp and 
regular; but if the edges are broken, the joints, when 
stopped, appear very wide and irregular, and are 
thought by some not to look well if the above pro¬ 
cess were not adopted. This method should never be 
permitted. 

Bastard Tuck Pointing is the name given when a 


88 


BRICKLAYERS’ GUIDE 


ridge in. to ^4 in. is formed on and off the stopping 
itself, as shown in Fig. 146, K. 

Masons’ V Joint, Fig. 146, L, shows the usual joint 
used for masons’ work. 

CHIMNEY BREASTS, FLUES, ETC. 

These have to be formed according to the design of 
the house; but in most cases, for the sake of economy 
in space, etc., the fireplaces are built, one over the 
other, from floor to floor, and frequently in party walls, 
the latter being the wall which divides house from 
house. The openings will differ in size, according to 
the range or grate used. For example, a full sized 
range would require an opening 4 ft. wide and I ft. 
10 Yz in. deep; the extra depth, beyond what is 
required for the flue, being lost when the flue is in 
position by arranging a set-off in the breast to form a 
mantel-shelf. For an ordinary register stove the 
opening would be 3 ft. wide by 12 in. deep, and so on, 
and, unless provision be made by a breast breaking out 
upon the outside of a building, a projection or breast 
must be formed inside the rooms to receive the stoves 
and provide for the flues. The back of the fireplace 
should not be less than 9 in. in thickness; therefore 
the projection of the breast depends upon the thick¬ 
ness of the main wall and style of stove to be used. 
That is to say, if the depth of the fireplace be 1 ft. 1 y 2 
in., then in an 18-in. wall with a 9-in. back to fireplace, 
the breast would project 4j4 in ; in a 14-in. wall, 9 
in., etc. 

It is most desirable to have as much bend as possible 
in flues; not to have the flues larger than is necessary 
(a kitchen flue should be 14 x 9 in., an ordinary living 
room 9x9 in.); to gather in quickly above the arch. 





























































































go 


BRICKLAYERS’ GUIDE 


though not so quickly as to form a nearly flat surface 
immediately above the fire; and to have perfectly easy 
bends, with no abrupt angles. For a flue to success¬ 
fully do its work, smoke should be treated as though 
it were water. Sharp turns and breaks interrupt the 



Fig. 149. Fig. 150. 


easy flow of the smoke, causing it to eddy round, 
choke the flue, and return again to the room. The 
inside should be smoothly rendered with pargeting, 
i.e., cowdung and lime, in the proportion of 3 to 1. 




IHSas a ii Bt fSf B 


Fig. 1 5 1. 


Fig. 152. 


This makes a smooth surface, is tough and is supposed 
to prevent the smoke stains and heat from coming 
through the wall. Ordinary mortar, however, is now 
more often used than pargeting. Fig. 147 is the sec¬ 
tional elevation of fireplaces over each 
other, as far as is possible, in a double- 
breasted wall; Fig. 148 being a cross- 
section taken through the double breast; 
Figs. 149, 150, 151 and 152 are plans of 
the same on the basement, ground, first and second 
floors; while Fig. 153 is a plan through the stack. 

Chimneys and flues maybe constructed at any angle 
on condition that any flue inclined at an angle less 
than 45 degrees is provided with suitable soot doors. 

Mistakes are often made in constructing flue? 


rrm 


B WhWhi 

Fig. 153 - 


































CHIMNEY BREASTS, FLUES, ETC. 


91 


through not carrying them fast enough to the right or 
left, as the case may be, so as to prepare for the fire¬ 
place above; then, when the mistake is discovered, 
they are carried over quickly, and a flat surface is 
formed, resulting in a faulty flue. To obviate this, an 
easy calculation should be made as soon as the flue is 
gathered over and brought into position above the 
fireplace. Taking Fig. 147 as an instance, the flue 
being in position 2 in. above the arch, measure the 
height to the fireplace above, and the distance the flue 
has to be taken to the right or the left; or, in other 
words, ascertain how many inches it has to be taken 
laterally to the foot vertically. In the case in point, 
F is the flue in position in the middle of a 6-ft. 4 in. 
breast. The distance to the fireplace above is 6 ft. 
and the 9-in. flue has to be carried to the right, allow¬ 
ing 4 y 2 in. outside work. Then it is evident that the 
left side of the flue has to be carried a distance of 2 ft. 
in 6 in. or 24 in. in twenty-four courses, to get into 
position; that is to say, the flue must recede on the 
under side, and sail over on the upper, 1 in. in every 
course. 

Fireplace Jambs.—When starting the fireplace in the 
basement, the jambs on each side will be solid, and are 
usually 14 in. on the face by the depth as already 
described. The flue, being taken either to the right 
or to the left, will appear upon the next floor as a 
jamb 18 in. on the face. This allows 4^ in. outside 
work, and a 9-in. flue. If, however, the flue should be 
14 x 9 in., then the jamb will be 23 in. on the face. 

As already stated, fireplaces vary from 2 ft. 6 in. to 
4 ft. in width, according to the stove to be used; and 
they will also vary in height, that for a kitchen being 
4ft., ^nd for an ordinary register 3 ft. high. When 


92 


BRICKLAYERS’ GUIDE 


the proper height is attained, an iron chimney bar is 
placed in position. This slightly curved bar (Fig. 154) 
is 3 in. wide, ^ in. thick, and rests 4^ in. each end 
upon the jambs, the ends also being split and turned 

half up and half down into the brick- _ 

work. An arch of two or three half- 
brick rings is then carried over upon Fig. 154. 
the chimney bar, and the work con¬ 
tinued above it (Fig. 155). Instead of the iron bar, 
lintels of coke breeze and cement, or an arch turned 
on a temporary turning piece, is now frequently used. 



Mode of Carrying the Hearth. —The hearth should be 
at least 18 in. wide, and extend beyond the fireplace 
opening 6 in. each way. There are several methods 
of supporting the hearth, but the most usual is by 
means of the trimmer arch. Turning pieces are fixed 
in between and at right angles to the trimmer T and 
the breast B (Fig. 156), covered with thin lagging, 
seen in section in the last named figure; the arch, con¬ 
sisting of rows of stretchers on edge and parallel to 
the breast, is then carried over and properly keyed in 
(see Fig. 157, which is a horizontal section taken 



































































CHIMNEY BREASTS, FLUES, ETC. 93 


through the fireplace, and showing the trimmer arch 
on plan). Another good system is that of tee-irons 
with the table turned downwards, fixed in between the 
trimmer and breast, sheeted with temporary boarding 
underneath, and filled in with concrete. Fig. 158 is a 
longitudinal section taken through such a hearth. Or 
the tee-irons may be fixed as already described, but 
kept such a distance apart as to allow a plain tile to be 
placed in between two adjacent webs lengthwise. 


Three courses of these tiles 


■L, 1 


1 -i 


rrr 


1 

TTT.. J... 1. 1 

| 

1 

J 

A~~r 

/lb 

_L_ 


t~ r r: j 


I'. ..I ‘I.. 


1.. 1 1 1 Q-yrn 


Fig. 157 . 


should then be laid and 
properly bonded 
in Portland cement 
and sand % Fig. 
159 is a cross-sec¬ 
tion illustrating 
the latter system. 
In each system 
the surfaces are 
brought to with 
concrete to within 
}& in. of the under 
side of the hearth, 
the in. being 
hearth, when there 
treated in the same 


allowed for bedding. The back 
has been no breast below, will be 
way as the front, but in all other cases will be bedded 
on the brickwork. 

Every flue should be complete in itself, for if open¬ 
ing be left in the 4^-in. walls—or withes, as they are 
termed—which part flue from flue, the smoke will 
enter the flue not in use, and a down current will take 
it into the room. 

Coring-holes 12x9 in. should be left, and temporary 
boards fixed in each flue and upon each floor, for the 
































































94 


BRICKLAYERS’ GUIDE 


purpose of clearing out the rubbish that may fall 
down the flue during the building. 

Corbeling. —If it should be necessary to increase the 
width of the breast, this may be done by corbeling 
the brickwork between the floor and the ceiling. By 
sailing over i y 2 in. per course on each side for three 
courses, the breast may be increased 9 in. (Fig. 147, 
A A). When anything beyond this is required, then 
stone corbels should be used. If the fireplace jambs 
are not carried up from the basement upon solid foun¬ 
dations, but grow out from the party wall, as it were, 
by means of corbeling, then the breast may project 
the thickness of the wall upon which it depends. 



Hard stone corbels are really more reliable than brick 
corbeling for this purpose. 

When the chimney breast has taken in all the fire¬ 
places and flues required, and appears above the top¬ 
most ceiling, the flues are brought into the position in 
which it is desired they shall be seen when above the 
roof. This, when out of sight, is done by dropping off 
the superfluous brickwork in offsets. But when the 
breast appears as a projection upon the outside of the 
building, then one method of reducing it is that 
shown in Fig. 160. 

Bond in Chimney Stacks.— Though it is far preferable 
to have 9-in. outside work to chimney stacks, to keep 
out both the rain and the cold, which retard the even 




























CHIMNEY BREASTS, FLUES, ETC. 95 


flow of the smoke, yet it is more often that the outside 
work is 4^ in. only. In bonding stacks, the desired 
end to be kept in view is that the withes or partings 
shall be tied in, so as to strengthen what might other¬ 
wise be a very weak construction. When the flues are 
surrounded with 9-in. work, either English or Flemish 
bond may be adopted. Figs. 161 and 162 are plans of 
alternate courses of the first, and Figs. 163 and 164 of 
the latter. It is with 4^-in. work outside that the 
great difficulty occurs, and up to the present a broken 



are indifferently tied in, has been used. In this bond 
a whole stretcher is used upon the quoin; but by 
sacrificing the small amount, if any, of extra strength 
derived from the use of the stretcher upon the quoin, 
and substituting a three-quarter bat in the stretching 
course, instead of using a closer in the heading course, 
the work may be built either in English or Flemish, 
and a perfect tie and bond be secured. (See Figs, no 
and in for plans of alternate courses of English, and 
Figs. 112 and 113 for the same in Flemish bond.) 

According to some strict building acts, chimney 
shaft or smoke flue shall be carried up to a height of 


















































































96 


BRICKLAYERS’ GUIDE 


Fig. 162. 


not less than 3 ft. above the roof, flat, or gutter adjoin¬ 
ing thereto, measured at the highest point in the line 
of junction with such roof, flat or gutter. And the 
highest six courses of every chimney stack or shaft 
shall be built in cement. 

Setting Ranges. —Built 
in and close fire ranges 
are many and varied in 
description; but there 
are general rules for 
guidance in setting 
them that are applica¬ 
ble to nearly all. Double-oven ranges are of course 
the largest, and the American or self-setting range 
the smallest. With the latter but little skill is re¬ 
quired, while the setting of the former is somewhat 
difficult. 

To proceed to set a range, the first necessary opera¬ 
tions are to properly level in a hearth or course of 

brickwork to take the 
oven cases; to tempo¬ 
rarily place the range 
in position so as to 
mark the flues, etc., 
and to build in beneath 
each oven case suffi¬ 
cient brickwork to allow 


n 


El 


Fig. 163. 


a 2-in. cavity below the oven. It will be found that 
the heat from the furnace traverses the top of the 
oven, and is then induced to descend on the outside 
or end of the range to the front of the check, which 
is a piece of sheet iron fixed diagonally on the bot¬ 
tom of the oven, and coming from the back extreme 
corner to within 4 in. of the front of the soot door in 










































































































CHIMNEY BREASTS, FLUES, ETC. 97 


the face of the bottom of the range, and centrally 
beneath the oven door. The flue at the end should 
cover as much surface as possible, and should not 
exceed 2 in. wide by the length of the side of the oven, 
the object being to keep the heated air and gas as 
close to the oven and over as wide a surface as 
possible. 

It has been described 
how the flue is formed 
to the front of the 
check; it is then allowed 
to go to the center of 
the back at the bottom 
of the oven, and from 
that point is taken up 
in a flue usually 9 in. or 10 in. wide and 3 in. to 4 in. 
deep, which ascends vertically to the damper, which is 
placed at the top of the back coving. The covings 
are sheets of paneled cast iron that encase the recess 
above the top plate, the covings, in their turn, being 



Fig. 165. Fig. 166. 

covered with a top plate. They are usually fitted with 
a plate rack, and should be bedded with mortar against 
the insides of the jambs and the brickwork at the back 
which is formed between the flues. 

The boiler is set on a benching of fire-brick built at 
the back of the ash pan and is usually arranged with a 
flue from the bottom of the furnace to the back of the 


















































































































98 


BRICKLAYERS* GUIDE 


range, and a vertical flue formed in a similar manner to 
the oven flue up to a damper placed at the top of the 
back coving. The boiler, which should be of wrought 
iron, is drilled and tapped for the connecting of the 
hot-water circulation. 

These are general methods, but special kitcheners 
often require different treatment. In every case there 
should be no sharp turns in the flues, and the top flues 
should be carried above the dampers in the direction 
of the chimney flue above. 



Register, Mantel Register, and Interior Stoves. —The 

main object in fixing these is to fill up with brickwork 
the space which, in the fireplace opening, is not occu¬ 
pied by the stove or flue. In some cases the register 
is placed in position, and set by filling in the brick¬ 
work through the register flap which forms the entrance 
to the flue for the smoke. These are often insuffi¬ 
ciently filled up, thereby leaving a large cold-air space 
at the top, which causes the smoke to be checked and 
sent back into the room, instead of pursuing its proper 
course up the flue. 

For interior grates with fire-lump backs, the shape 
of the back of the lump should be marked out upon 
the hearth, and brickwork built up to the shape, allow¬ 
ing for a mortar bed at the back of the lump. Here, 
again, it is important that the opening should be filled 
up as much as possible, leaving only the size of the flue. 



















































ARCHES AND GAUGED WORK 


99 


ARCHES AND GAUGED WORK* 

Gauged work consists in rubbing and cutting to any- 
required shape specially made bricks, or “rubbers,” 
as they are technically termed. 

This class of work is usually done in what is called a 
cutting shed, provided with a bench about 2 ft. 3 in. 
high and 2 ft. 6 in. wide. 

The tools and appliances required are a rubbing 

stone, circular in shape, 
and 14 in. in diameter; 
a bow saw fitted with 
twisted annealed wire 
No. 18 gauge, parallel file 
16 in. long, small tin scrib¬ 
ing saw, square, bevel, 
straight pieces ot gas 
barrel for hollows in 
mouldings, etc., bedding slate to try the work for 
accuracy, straight-edge, compass, setting trowel, putty 
box (Fig. 169), boaster, club hammer, and scotch (the 
three latter for axed 
work), reducing boxes 
for thickness (Fig. 170), 
and for length (Fig. 

171), moulding boxes 
(Fig. 172), boxes with 
radial sides for obtain¬ 
ing the wedge-shaped 
voussoir according to the template (Fig. 172^), a 
setting-out board about 6x5 ft. and lining paper 
2 ft. 6 in. wide, etc. 

The most elementary kind of gauged work is that 

♦This department is largely taken from H. W. Richards’ work on 
“Brick laying and Brick-cutting.” 














TOO 


BRICKLAYERS’ GUIDE 


which is known as plain ashlar, consisting of heading 
and stretching courses for plain facing. The opera¬ 
tions are as'follows: first bed the brick, i.e., place the 
brick with the letter or hollow side on the rubbing 
stone; then, holding the brick with both hands, rub it 
upon the stone, giving it a circular motion from right 
to left, and trying it occasionally with a straight-edge 

till the bed of the brick 


B 














A 



has become a perfect 
plane. 

Next, with the rubbed 
bed turned from the 
body, place the side or 
Fig . I7I face of the brick upon 

the stone, and rub as be¬ 
fore, at the same time endeavoring to make the side 
square with the bed, testing it by application of the 
square, stock to the side, and the blade to the bed 
of the brick. Then serve the head in the same way, 
making it square 
with both bed and 
face. After these 
operations are per¬ 
fect, the brick has to 
be reduced to thick¬ 
ness; this is done by 
placing it on its bed 
in a reducing box (Fig. 170), the measurement of the 
inside depth of which is T yin. under 3 in., sawing off 
the superfluous material and finishing with a file. 

If for a stretcher, next place the brick face down¬ 
wards in a g-in. lengthening box (Fig. 171), making 
the square end to coincide with the front edge A of 
the box, and saw off to length, finishing with a file at 



















MICHES AND GAGGED WORK 


i o* 


the back edge B. The cut stretcher will be 9 in. less 
3^ in. in length. 

In preparing long headers, the brick would have to 
be placed in the same box, face downwards, but the 

saw and file would 
be used along the 
top edge of the 
box, thus making 
the header 4^ in. 
less 3V in. in width. 

If for bat head¬ 
ers, then the 
squared end is placed downwards in the box, and saw 
and file used along the top edge again. 

Arches. —These may be plain, axed or gauged. 

In plain or rough 




arches the bricks are 
not cut at all; the joints 
alone give the radia¬ 
tion, and the arch is 
usually made up of 
rings. 

The Relieving Arch.— 

The relieving or dis¬ 
charging arch (Fig. 173), 
as its name implies, is 
used for the purpose 
of relieving the weight 
from any portion of the 
building which is too 
weak to bear it, and dis¬ 
charging or transmit¬ 
ting it to piers, etc., specially prepared to receive the 
load. They are sometimes used in the face of build- 


Fig. 173- 


A. RGB 




























102 


BRICKLAYERS’ GUIDE 


ings, when they are also treated as ornamental features. 

The most frequent use for the relieving arch is 
inside the building, over door and window openings. 
The opening is first bridged by the lintel, which should 
rest not less than 4^ in. upon the jambs each side of 
the opening; next a brick core is built throughout the 
entire length of the lintel, to serve as a turning piece 
for the arch; the curve being obtained by means of a 
curved mould having the same rise it is intended to 
give the arch. This is applied to the face of the core; 
the bricks are marked, and then cut to shape. A 
skewback, which should radiate from the striking 
point, is built at each end of the lintel; and the arch, 
consisting of 4f4-in. brick rings, but starting with a 
stretcher at each end upon the skewback, is then 
turned over the core. When a flat rise only is given, 
the brick core is done away with, and the curve is 
worked upon the lintel. 

It must not be forgotten that the lintel is in length 
the exact span of the arch; that the object of the 
lintel is for the purpose of fixing the joinery; that the 
core acts only as a turning piece for the arch, and to 
fill up the space between this and the lintel; and that 
neither of them influences the strength of the discharg¬ 
ing arch in any way. Should a fire occur, the lintel 
would burn and the core fall, but the arch ought to 
remain intact. The method of striking out the arcl 
will be the same as that given for the segment. 

When arranging the rings, those starting from the 
top and working downwards alternately should always 
have a key-brick; the other rings will key in with a 
joint. As already stated, in this as in all other rough 
arches, the bricks themselves are square, and the 
radiation is obtained by means of the joint. The 


ARCHES AND GAUGED WORK 


103 


mode of drawing the radial joint is as follows: prick 
over the 3-in. courses and fill in the face from the 
radial point R, as in the semi-arch. Through the 
radial point, and parallel with the lintel, draw an 
indefinite line A B; make one of the courses or bricks 


of the arch parallel, by keeping the top equal to the 
bottom of the brick; produce the line which does this 
so that it cuts the line A B, in C, then C will be the 
point by means of which a line drawn from it through 
the soffit end of the face joint of each course will give 
the radial joint. 

This method must 
be followed each 
side of the arch. 

The Invert Arch. 

—It often occurs 
that the principal 
loads in buildings, 
such as girders 
carrying the floors, 
etc., are concen- j" 

trated upon cer- [_ 

tain points, as 
piers, for instance, 
which are usually strengthened to receive them. 

Should there be openings upon each or 
one side only of the pier, it is very evi¬ 
dent that the weight of the pier and its 
load would be taken vertically downward 
to one part of the footings only, little 
able, perhaps, to bear it. 

To relieve the special part of some of 
the weight, by spreading it over a larger area of foot¬ 
ings, invert arches are used, as in Fig. 174. Her* 3 


s 

TEMPLATE 



Fig. 174/4- 



Fig. 174 . 

























104 


BRICKLAYERS’ GUIDE 


some of the weight is taken from the pier A and its 
fellow, and transmitted, by the invert arch, to the 
footings in between them. It will be noticed that the 
lines from the radial point to the skewbacks form an 
angle of 45 degrees, this being found to be the best 
angle to receive the weight. 

Chimney breasts in basement stories are often treated 
in this manner. 

Egg Shaped Sewer (Fig. 175).—This sewer, as its 
name indicates, is shaped like an egg, with the smaller 
end downwards, this shape being found the best 
adapted for the varied charge of sewage. It matters 
little whether it be during a time 
of storm water, or during a dry 
season, when there is but small 
quantity of sewage, there is 
always a sufficient depth of mat¬ 
ter to ensure a perfect flow. The 
sewer may consist of two or three 
4^-in. rings of brickwork, with 
a terra cotta or hard-brick invert; 
bedded in concrete. The mode 
of setting it out is as follows: Let AB be the diame' 
ter of the head, or crown, then CB will be the radius, 
and C the radial point; measuring out from the center 
C to the left and right of A and B, a distance equal 
to AB, will give the radial points D and E, from 
which the curves of the sides may be described; 
then, for the invert, draw from the point C at right 
angles to AB a line CF equal to AB. By dividing 
CF into four parts, the radial point G will be found. 
The termination of the sides x , x , and the beginning 
of the invert is determined by lines passing from D 
and E through G. The 4^-in. rings will be arranged 



Fig. 175. 


ARCHES AND GAUGED WORK 


105 


as in the relieving arch, the outer rings having the 
key bricks, one at the crown, the line FC passing 
through the center; and what might be termed two 
keys, one on each 
side, the line DE 
passing through 
their centers; the 
next ring towards 
the inside having 
straight joints at 
these points; the 
next inner ring, 
keys, and so on. 

Axed Arches.— 

Axed arches are 
really roughly cut 
gauged arches with 
a T \-in. mortar, in¬ 
stead of a sVin. 
putty joint. There¬ 
fore, the mode of 
obtaining the tem¬ 
plate and the system 
adopted for gauged 
arches generally, ap¬ 
plies equally well to 
axed ones; the only 
difference being that 
when the bricks are 
hard, the brick will 
have to be scribed each side to the template and across 
the soffit with a tin scribing saw, and cut off to the 
scribed lines with a boaster (sometimes called bolster) 
and club hammer upon the banker, and the remaining 



Fig. 177. 














io6 


BRICKLAYERS’ GUIDE 


material between the scribed and boastered lines 
neatly axed off with a scotch (sometimes termed 
scutch). 

In arches in which the end or soffit may not be cut to 
a bevel, such as glazed bricks, etc., the mode of apply¬ 
ing the template to the face of the brick is somewhat 
different. It would simplify the matter, perhaps, if, 
after the template was obtained, as described, the bot¬ 
tom of the template were to be cut off to the cutting 
mark, and made to fit the soffit line of the drawing of 
the arch and then applied to the face of the brick, the 
brick and template both being on end, and both the 
bed and back of the brick cut off to the template. 
That is to say, both edges of the template would be 
cutting edges (Fig. 174^, which shows the template 
in position for cutting the brick). 

Gauged Arches.—Throughout this work one principle 
is adopted for setting out and obtaining the templates 
for all gauged arches, and by careful attention to 
the instructions given, all practical men should be able 
to gain a perfect mastery of the subject. Whenever 
the compass is mentioned, it will be understood that 
in full-size work the radius rod would be used, and 
although, when describing the construction, the whole 
of the arch is alluded to, a half only is drawn, as would 
be the case when setting out in practice. 

The Semicircular Arch.—This arch is known always 
as the semi (Fig. 176), the opening here being 3 ft., 
the face 9 in., and the soffit 4^ in. 

Construction , etc.: Draw an indefinite base line; 
upon and perpendicular to it erect a center line; upon 
the base line set out the opening AB, half each side 
of the center line; then with the point of the compass 
at the cp«.*> C, and the pencil at B, describe the 


ARCHES AND GAUGED WORK 107 


larger half of the soffit, or intrados, and with the point 
still at C, but the pencil extended 9 in. beyond B, 
describe the outer line or extrados. In most rubber 
bricks the brick and joint together will hold out or 
measure 3 in. Therefore 
take a distance of 3 in. in the 
dividers, and starting with 
half the distance each side 
of the center line on the 
extrados, prick over till the 
courses come home exactly 
to the springing line, increasing or decreasing the dis¬ 
tance taken in the dividers, i.e., making it slightly 
over or under 3 in.; but always taking care that the 
first pricking, or key-prick, shall be equally divided 
half each side 
of the center 
line. Call 
these first two 
prickings D 
and E. From 
the center C, 
through D and 
E, draw the 
approx i m a t e 
key, but pro¬ 
ducing the 
line through 
E to H. This 
approx i mate 
key will also be the shape of the trial template. 

To obtain the template the following pieces are 
necessary: two small straight-edges 16 x 2 x x / 2 in., and 
also a piece of board 14 x 33^ x in., with both sides 
































io8 


BRICKLAYERS’ GUIDE 


planed and one edge shot square and true. Place the 
latter, which may be termed F, Fig. 176, with the shot 
edge against the line radiating from C to D, and with 
a long straight-edge having the end of one edge 
against the radial point C, and 
the other end coinciding with 
the produced line H, and lay¬ 
ing over F, mark the latter the 
shape required. Having cut 
and shot the template to the 
line drawn upon it and square 
with the face (when it will Fig. 181. 

appear as F, Fig. 1765^), pro¬ 
ceed to traverse it; i.e., see that in pricking over 
there are fourteen courses in half the arch, including 
the key; ascertain whether fourteen such templates 




Fig. 182. Fig. 183. 

will exactly fill half the arch, starting with the key and 
terminating with its edge upon the springing line. 
The way to traverse the template is as follows: Place 
the template upon the approximate key, taking care 

that it exactly 
F fills it; draw a 

pencil line, 
C which will be 
known as the 
filling-in mark, 
across the left-hand edge of the template and 
immediately over the soffit line. Next place the 
two straight-edges O and X one upon each side of 
and tight up to the template, always keeping O a 


















ARCHES AlNlD GAUGED WORK 


iog 

little above the filling-in mark, Fig. 176^. Keep 
X firmly in its place, remove the template, slide O 
against X, remove X, place the template against, 
with the filling-in mark on the soffit line; place X 
against it, remove the template, slide O against X; 
and repeating this movement till the right-hand edge 
of the template comes out to the springing line. 
Should the template at the last turn be parallel to the 
springing line, but not quite home to it, bring the tem¬ 
plate down a little by placing the filling-in mark higher 
up. The top may come over the springing line, and 
the bottom reach or not quite reach home; then a 
shaving or two must be taken off the top, or if the bot¬ 
tom comes over, then a few shavings off this. Each 
time it becomes necessary to alter the fijling-in mark 
or the template itself, it will be necessary to traverse 
again, taking care always, at the start, that the tem¬ 
plate is equally divided, half each side of the center 
line. When the template has been obtained, line in 
the joints of the arch with it. The next important 
matter is to allow for joint. This is done by placing 
the edge of the template against the radial line CD, 
backing it up with the straight-edge O kept firmly in 
position; then, by sliding the template up against the 
latter, it will recede from the radial line CE. If for 
axed work the template may be worked up till it leaves 
the radial line CE by in.; if for gauged work, by 
Jz in.; then, in a similar way to that in which it was 
marked for filling in, scribe for cutting mark imme¬ 
diately over the soffit line, Fig. 176, S. When for 
gauged work, to prove that the amount allowed for the 
joint is correct, traverse the template again, with the 
cutting mark on the soffit line, for four courses, when, 
If it leaves the fourth line by in., it may be taken 


iio 


BRICKLAYERS’ GUIDE 


as correct. In this arch the lengths of all the courses 
are alike, and may be taken on the edge of the tem¬ 
plate, bearing the cutting work; this edge being termed 
the cutting side of the template, and the other the 
bed, coinciding in this respect with the arch-brick 
itself. Place the bed of the template against the 
radial E, with the cutting mark upon the soffit line, 
then on the cutting side make a marie on the edge 
immediately over the extrados (these marks should 
always be squared across). While the template is in 
this position, the bottom and top bevels B may also 
be obtained, by making similar squared lines on the 
bed of the template, and then connecting these on the 
face, as in Fig. 177^. 

In using the template, the soffit bevel will be taken 
off by placing the blade of the bevel or shift stock 
against the bed of the template, the blade pointing 
towards the soffit and agreeing with the line upon the 
face of the template. It is advisable to write the size 
of the opening, the name of the arch, and the number 
of courses upon the template, and also to apply the 
center (Fig. 178), upon which the arch will be turned, 
to the striking out, ticking off the courses upon it, and 
squaring them through; this will act as a guide to keep 
the proper thickness of joint when setting the work. 
The setting out should be on lining paper, which may 
be saved for future reference. 

How to Cut a Semi-Arch.—Bed the brick and square 
the face; square the head from the face, but bevel it 
from the bed, the stock being placed against the bed, 
and the blade to the head. These bricks must be pre¬ 
pared for right and left hand; that is to say, with the 
face of the brick turned towards the body, half the 
beds should point towards the right and half towards 


ARCHES AND GAUGED WORK 


in 


the left. Then prepare a radiating box io in. wide in 
the clear, and rather longer than the template, the 
sides of which, worked from a square line across the 
bottom, radiate exactly as the template, Fig. 173, also 
having the cutting mark upon each side exactly oppo¬ 
site each other. Great care must be taken that the 
box is accurate, and it is advisable to try the first radi* 
ated brick upon the bedding slate, with the original 
template. Two bricks, right and left hand, may be 
placed in the radiating box, with their faces to the 
sides and their soffits to the cutting marks, and sawn 
close to the top edges of the sides of the box (the lat¬ 
ter being protected with tin), and finished with the 
file, taking care to file away from the front arris of 
side of the box, so that the former may be perfectly 
sharp; then, in a lengthening box (Fig. 171), facedown- 
wards, and with the soffit placed tight against a 
straight-edge held across the end, cut off to a length 
of 9 in. 

If the arch is more than 9 in. on the face, then, 
before radiating, the course must be made up in 
length. Taking an arch 12 in. deep on the face, as an 
instance, and dealing with a course having a stretcher 
towards the soffit, the stretcher will be cut off 8 in. in 
length, and the opposite bevel obtained in the length¬ 
ening box. A bat over 4 in. in length, bedded, faced 
and beveled, will be fitted to the top of this, the tem¬ 
plate applied, the brick scribed to the length of the 
cutting side, and to the square mark on the bed, the 
twc marks cn the brick connected by the scribing saw, 
and sawn off square with the face. By this means the 
course is cut off to length, and the top bevel obtained 
at the same time. 

It mav here be noted that the 9-in. lengthening box 


112 


BRICKLAYERS’ GUIDE 


can be used for any odd measurements, by nailing a 
stop or fillet across the bottom of the box and parallel 
to one squared end, according to the length required, 
the worked end of the brick being placed against the 
stop, and the piece not required cut off to the end of 
the box. 

For an arch having a 9-in. soffit, it will be readily 
understood that a face stretcher would have to be 
taken to a depth of 4^ in. in a reducing box and 
backed up with a properly squared and beveled bat, 
and that for a soffit stretcher the brick would be 
bedded, the face beveled for the soffit, and the 
header, acting as the face, squared from the bed and 
soffit. By placing this brick soffit downwards in a 
reducing box 4^ in. deep, the opposite bevel, after 
sawing, would be worked upon it; being afterwards 
made out, on the face, by a bedded, squared, and 
beveled bat, and cut off to length, to the template. 

Every arch should b*e keyed in with a stretcher 
towards the soffit; and it will be found that, counting 
the courses in half the arch, and including the key, if 
there be an odd number, then there will be a stretcher, 
for the start or upon the skewback, and a stretcher for 
the key; if an even number, then a header for the 
start, and a stretcher for the key. 

Arch with Moulded Soffit.—In arches with moulded 
soffits, although the end in view, with respect to 
bevels, etc., is the same, the mode of working is some¬ 
what different. The section of the mould required 
must be cut upon two boards, 10 x 4^ x ^ in., 
screwed together, the edges shot and squared, and 
the moulding cut upon them while thus fixed, so that 
they shall be exactly similar; the edges representing 
the face and soffit may be protected by tin, and they 


ARCHES AND GAUGED WORK 


113 

should be fastened one on each side, exactly opposite 
each other, to a box having a stout bottom and two 
sides only, and being about 10 in. in the clear after the 
moulds' are fixed (Fig. 172), the bricks being properly 
bedded and roughly squared upon the side which is not 
intended to be the face. The bevel is taken from the 
template in the usual manner, and marked upon the 
bottom of the box, both right and left, with the back 
of the stock against the front edge of the box and the 
hind part of the blade on the bottom; the roughly 
squared edge of the brick between the roughly squared 
face and the bed is fixed against the line or lines thus 
marked (if there be room, two bricks at a time may be 
cut, one for right hand and one for left); the saw is 
taken through the moulded soffit and the top face, and 
then with file, barrel, etc., the brick is finished, being 
beveled, moulded and faced at the same time. When 
the brick is taken out of the box, should the soffit, or 
face, be not quite true, the bed is rubbed to fit them , 
the square and bevel being used for tnis purpose. 
The remaining operations are the same as in plain- 
gauged arches. 

Setting. —The center, Fig. 178, having been fixed 
with folding wedges beneath it, so as to make it easy 
of careful removal after the arch is set, should be 
tested for accuracy. 

Axed arches are set in fine mortar, the joint being 
either struck, or raked out, and afterwards pointed, to 
give it a fancied resemblance to gauged work. 
Gauged arches and gauged work generally are set in 
lime putty, as already described. The putty is served 
to the setter in a putty tub. This is a box open at 
the top and with beveled sides, being about 15 x 12 in. 
at the top, but smaller at the bottom, and about 9 in. 


BRICKLAYERS’ GUIDE 


114 

deep (Fig. 169). The setter, keeping the putty fre¬ 
quently stirred, and having knocked and brushed the 
dust off the brick, holds it lightly on the top of the 
putty, takes up just sufficient to form the joint, removes 
a small quantity from the center, makes the joint true 
at the edges, puts the brick in position, and lightly 
taps it to make it solid. Arches are started from the 
right and left hand, and worked up towards the key, 
which is put in last. When the arch is completed in 
its place, it is grouted in with Portland cement, a 
joggle having been formed in the brick by cutting a 
groove I x ^ in. in the middle of it; this grouting in 
with Portland cement greatly strengthens the arch. 
In years past, a bead was formed with the joint, and 
the work left. But now, any irregularity in the face, 
mouldings, etc., is corrected by means of files, pieces 
of barrel, brick, handstone, etc., both brick and joint 
being left flush and brushed down with a soft brush. 

The Segment Arch (Fig. 177^).—Opening, 3 ft.; rise, 
6 in.; face, 12 in. Draw an indefinite base line, and 
at right angles to it above and below draw an indefinite 
center line. Upon the base line set out the opening 
AB half each side of the center line CD, and above 
the base line measure off the 6-in. rise in E; then with 
the point of the compasses at A, and taking any dis¬ 
tance greater than half AE, describe arcs above and 
below the base line; with the same distance in the com¬ 
passes and the point at E, cut these arcs in X. Then 
a line being drawn through these intersections and 
meeting the center line, will give the radial point O. 

With the point of the compasses at O, and the pen¬ 
cil extended to A, describe the soffit, passing through 
E and terminating at B. Next with the straight-edge 
at O and passing through A, draw the skewback or 


ARCHES AND GAUGED WORK 


US 

abutment, and the same with B; then measure up from 
the soffit upon the center line 12 in., and with the 
point of the compasses at O, and the pencil extended 
to the 12 in., draw the extrados terminating at the 
skewbacks. Now proceed as in the semi to procure 
the template, with this exception, that the work termi¬ 
nates on the skewback, and not on the springing line. 
Having procured the template, fill in the arch. The 
courses will be divided into 8-in. stretchers and 4-in. 
headers, taking care to key in with an 8-in. stretcher 
towards the soffit. This arch having a skewback, care 
should be exercised that this is properly cut and set, 

especially if it be in 
ordinary building 
bricks. A mould or 
gun, as it is termed, 
should be taken off 
the drawing and ap¬ 
plied to the reveal; 
the projecting or tri¬ 
angular portion an¬ 
swering to the fall of 
the skewback (Fig. 
177 / 4 )- Here A being placed against the reveal, 
the skewback is built up to B. 

In this, as also in the semi-arch, if the student 
wishes to draw the arch only, then the extrados may be 
pricked over at 3 in. as already described, and the face 
joints filled in from the radial point by means of a 
straight-edge passing from it to the divisions on the 
extrados. 

Moulded Segment. —When a moulding is worked upon 
the reveal and continued round the soffit of the seg¬ 
ment, a new difficulty presents itself in the intersection 














ii6 


BRICKLAYERS GUIDE 


of the mouldings between these two. Again, take a 
3~ft. opening, 6-in. rise, 12-in. face, with a 2^-in. 
moulding, the half being shown (Fig. 179). Set out the 
soffit and reveal as in the plain gauged segment; then 
to the right of the reveal line measure off the depth of 
the moulding 2% in., draw the outside moulding line 
parallel to the reveal line, and continue above the base 
line. Then on the center line and above the soffit 
again measure off the 2^-in. moulding, and with the 
point of the compasses at O and the pencil extended 
to the 2^-in., describe the moulding line parallel to 
the soffit, and meeting the reveal moulding in point F. 
From the point F to B draw a line. This will be the 
miter line. The skewback will be taken, as before, 
from the point O, but will begin at the point F. The 
arch will be cut precisely in the same way as the 
moulded semi, with a slight addition to the top course 
of the moulded reveal and the first course of the arch, 
i.e., where the intersection takes place. Two pieces 
of board, iox 3 x ^ in., should be planed and shot 
while screwed together, so that they shall be perfectly 
true in themselves and to each other; the lines H and 
I will be produced each way and the moulds laid to 
coincide with the bricks S, Fig. 180; then by means of 
the straight-edge, which is made to coincide with the 
produced lines as shown, the lines H and I will be 
accurately drawn upon the moulds. They should then 
be cut to this shape, and are known as shoe moulds. 1 
A moulded brick, being placed on its bed in between 
two shoe moulds, can, by means of the saw and file, be 
properly mitered as M, Fig. 179; the moulded end of 
No. 1 course of the arch should be then cut to tightly 
fit it. All other operations for the moulded segment 
will be the same as in the moulded semi. 


ARCHES AND GAUGED WORK 


n 7 

In axed arches with field-moulded bricks (bricks 
having the moulding cast upon them in the brick-mould 
while in the green state, and afterwards burnt), such 
as bull-nosed and mopstaff beaded, the treatment of 
the miter will be nearly the same, only, that instead of 
the miter being solid, as in M, Fig. 179, the portion 
BF in the latter figure will be cut upon the top of the 
brick, and the skewback taken from that, Fig. 181- 

Camber Arch.—This is sometimes called a straight 
arch; but it has really a slight rise, the rule being to 
give the soffit a rise of ^j-in. for every foot of opening. 
The reason for giving the rise is to counteract the 
optical illusion 
which causes the 
arch, if straight 
upon the soffit, to 
appear to sag, or 
camber, the wrong 
way. When a 
slight rise is given, 
the arch appears * Fig. 186. 

to be straight upon 

the soffit. It would be impossible to strike such 
a slight sweep with a radius rod; the rise is there¬ 
fore given by means of the camber slip. A camber 
slip should be made of good hard wood that will 
not shrink or twist; mahogany or oak is excellent for 
this purpose. It is always convenient to keep one in 
stock, and if it be long enough it will answer for any 
opening. There are not many camber arches over 7 
ft.; therefore a convenient length for the camber slip 
would be about 8 ft. The mode of obtaining the 
camber slip is as follows (an extreme case is given, as 
being easier of illustration): Suppose the opening to 





















n8 


BRICKLAYERS’ GUIDE 


be 3 ft., and the rise I in. to the foot, then the camber 
slip 3 ft. long would have a rise of 3 in.; take a rod 3 
ft. long, measuring in width 1 in. at each end and in 
the middle 2 y 2 in., or in other words, having in the 
center half the required rise; shoot this piece from the 
middle to the two ends perfectly straight, thus form¬ 
ing two triangles, as it were, upon a common base; 
call the center B, and the two outside points A and C 
(see Fig. 182). Then take a piece of board a little 
over 3 ft. long and 6 % in. wide by x / 2 in. thick, planed 
both sides, and one edge shot, draw a center line upon 
the face of it, and 18 in. each side of it draw two other 
lines; call the center line E, and the two outside lines 
D and F, Fig. 183. Upon the center E, 6 in. up from 
the shot edge, drive in a pin, and upon D and F, 3 in 
up from the shot edge, drive in other pins. Then take 
the first piece, Fig. 182, already prepared, and with a 
pencil held at the center B, apply it to pin F, and 
with A on the same piece pressed against the pin E, 
move the piece with the pencil from F to E, describ¬ 
ing half the curve, Fig. 184. Repeat this process on 
the other side, moving the center B with the pencil 
from D to*E, and the curve will be drawn; then cut 
the curved side to the line drawn, and the camber slip 
will be completed. To prove the camber slip, lay it 
down and mark all round it, then reverse it, and if the 
camber slip coincides with the lines drawn by it, it 
will be correct. In using the camber slip always work 
from a center line. 

The next consideration is what amount of skewback 
should be given to the camber arch. By the old sys¬ 
tem the opening was taken as a radius and a line cut 
upon the center line as a radial point for the skewback; 
but this has been found to give too great a skewback 


ARCHES AND GAUGED WORK 


iig 


and becomes a source of weakness. The proof of this 
;s as follows: First considered as a wedge, sustaining 
a vertical thrust or load. If a wedge were made too 
flat, when driven home the ends would become bruised 
and split. Again, let it be supposed that the camber 
arch is taken out of the segment, or let it be consid¬ 
ered that behind each camber there is an invisible seg¬ 
ment; then, as far as strength is concerned, the more 
of the segment contained in the camber, the stronger 
the arch; experience shows that the longer the radius, 
the less the rise, or the flatter the segment, and hence 
the more of it in the camber The less acute skew- 
back, if produced to meet a center line, will give the 
desired longer radius. Therefore a good datum to 
work to, as a general rule, is to give each skewback 
I in. fall for every foot of opening, when the arch is a 
foot upon the face. 

To Set Out the Arch.—Opening, 3 ft.; face, 14 in., 
Fig. 185. Draw the usual base line, with a center line 
perpendicular to it; set out the opening AB, half each 
side of the center line CF. Then, with the center of 
the camber slip upon the center line, and the edge just 
coming out at the points A and B, draw the camber or 
curved line. 

Then to obtain the skewback. At A and B erect 
faint perpendiculars, and upon these lines measure, 
from the base line upwards, distances of 12 in. and 14 
in.; take square lines to the left of A and right of B, 
and upon these lines at the 12-in. height measure off 3 
in., the allowance for an arch 12-in. face and 3 ft. 
opening; then from A and B, through the outer points 
of the 3-in. lines draw the skewbacks indefinitely. 
These skewbacks would answer for any depth of face 
for this size opening. Now take a point upon the 


120 


BRICKLAYERS* GUIDE 


center line, 14 in. up from the base line, place the 
center of the camber slip upon this point, the curved 
edge at the same time passing through the two 14-in. 
points upon the perpendiculars erected at A and B, 
and while in this position draw the outer or extrados 
line. Prick over the courses upon this line, as in other 
arches, starting with the key and working out to the 
skewback. If it were possible to produce the skew- 
back downwards to meet the center line, then this 
point might be treated as the radius point wherewith 
to fill in the approximate key. But should this not be 
practicable, the number of courses taken upon the 
extrados line, by reducing the distance taken in the 
dividers, will have to be pricked over on the intrados 
line, taking care, at the same time, to have an equal 
proportion on each side of the center line. Having 
pricked over the top and bottom lines accurately, draw 
in the approximate key, but producing the line to the 
right of the center line, both above and below the 
arch. Call this produced line DE. Now, to procure 
the approximate template; as before, prepare a piece 
of x /i- in. board, 3^ in. wide and 18 in. long, both 
sides planed and one edge shot. Let the shot edge 
be exactly placed against the left-hand line forming 
the key, and, with a long straight-edge placed over 
the board, the edge coinciding with the produced line 
DE, mark the template. Cut and shoot it accurately, 
and traverse as before. Having obtained the tem¬ 
plate, fill in the courses, and fix the cutting mark. It 
has already been seen that in the semi and segment 
the courses have been equal in length, and the bevels 
alike, but in the camber the bevel and length will 
differ in each course; the longer bevel and length 
being in No. 1, and the shorter in the key. An illus* 


ARCHES AND GAUGED WORK 


121 


tration of the treatment of No. I course will serve for 
all the courses. No. i course is the first course upon 
the skewback. Place the template with its bed side 
upon the right-hand skewback line, and the cutting 
mark upon the camber line. Then, where the edges of 
the template touch the camber lines, both top and bot¬ 
tom and on both edges make pencil marks. One mark 
(the cutting mark, it will be remembered) is already 
made. Square these marks upon the edges, and con¬ 
nect the two top and the two bottom across the face of 
the template; this will give the length of the course 
upon the cutting edge, and the bevels both bottom and 
top. Serve each course in the same way, and number 
their bevels upon the template. The arch is 14 in. on 
the face; it will therefore be filled in as 8-in. stretcher, 
2-in. closer, and 4-in. header, in one course, and 4-in., 
2-in., and 8 in., in the next, and so on, as before, key¬ 
ing in with a stretcher towards the soffit. The skew- 
back will be treated as in the segment, and all other 
operations in setting, etc., will be the same. Great 
care should be taken in grouting in this arch, as it is 
one of the weakest in construction. 

It must be remembered, in cutting this arch, that 
the different bevels have to be taken off and marked 
“right” and “left,” upon the bottom of the box, as 
was done in the case of the one bevel in the segment 
arch. 

Moulded Camber (Fig. 186).—The moulded camber 
should be treated similarly to the moulded seg-nent, 
the outside line of moulding being drawn in with the 
camber slip, parallel to the soffit, meeting the outside 
line of moulding on the reveal and forming the miter. 
The skewback must be taken extra to the moulding, 
or, in other words, it must be drawn from the outside 


122 


BRICKLAYERS’ GUIDE 


point of the miter, so that if a 2^-in. moulding be 
used in a 3-ft. opening, with an arch 12 in. on the face, 
the top point of the skewback would fall 53^ in. away 
from the reveal. The shoe mould, etc., would be 
obtained as in the segment arch. 

Camber on Circle.—Arches circular on plan are not to 
be recommended, as being of weak construction. But 
where it becomes necessary to use them, they should be 
strengthened by means of an iron barbent to the shape. 

The mode of setting out this arch and obtaining the 
template is very simple. Let Fig. 187 be the plan of 
the sweep to be covered by a camber arch, of which 
AB and CD are the outer and inner faces respectively. 
Develop AB by pricking it over with compasses, or 
bending a thin lath round the curve and bringing it 
out as the straight opening EF. Upon EF construct 
the camber arch in the ordinary way (Fig. 188), and 
produce the lines of skewbacks, bringing them down 
indefinitely below the soffit or base line. Next 
develop the inside line CD of the plan in a similar 
manner to AB, cutting off its actual length on a rod; 
then lay the rod in between the skewbacks which are 
produced below the soffit, till, while keeping it paral¬ 
lel with the base line, it accurately fills in between the 
skewback lines. Now, with the rod in this position, 
draw a line which may be termed a sub-base line, and 
draw the camber line upon it. Next procure the tem¬ 
plate as already directed, taking care that it be long 
enough, not only for the ordinary arch, but also to 
cover the bottom or sub-camber line. Having got the 
bevels, cutting mark, etc., while the latter is upon the 
soffit line proper make another cutting mark also upon 
the bottom soffit line, and the template will be ready 
for a camber on circle. 


ARCHES AND GAUGED WORK 


123 


When cutting the arch, the upper cutting mark must 
be used for the face of the arch-brick, while keeping it 
at the soffit, and the lower cutting mark will be used 
for the back of the brick, while keeping it in a similar 
position. By cutting this brick, the student will learn 
how to prepare the radiating box, one side of which 
will be higher than the other, according to which side 
of the arch is being cut. Or, in other words, let it be 


Fig. 187. 




granted that the left, or leading hand of the arch, is 
the one to be radiated. Then, having drawn a square 
line across the bottom, and parallel to the tail of the 
box, with the face of the brick turned to the body, and 
the soffit towards the right hand, prepare the box by 
placing the upper cutting mark of the template against 
the body, and the lower one of the other side, to this 
line. 


















124 


BRICKLAYERS’ GUIDE 


Should the curve be very sharp, it would cause the 
arch, if left after the above operations, to appear, on 
the face, as a series of short lines. To avoid this a 
pair of moulds io in. long, having the same sweep as 
the plan of the arch struck upon them, and 4% in. 
only at their widest point, should be prepared. Each 
course, being laid in between these moulds according 
to the angles their beds make with the base line (for 
instance, the key-brick will lie at right angles between 
the curved sides), would, when cut, receive the same 
curve as the plan, Fig. 188. It must be borne in mind, 
when putting in the skewbacks, that they are radii of 
the same sweep. 

Should the face of this or any arch be 18 in. deep, 
then the bonding will be as in Fig. 190. 



Fig. 189. 


n~nr 


mr 


Fig. 190. 


It will be noticed that the skewback of the 12-in. 
segment, Fig. 179, does not come out to the top of the 
course, making it necessary to put in a small piece of 
brick; and again, that the 14-in. camber, Fig. 186, is 
not in depth the multiple of a brick course, necessitat¬ 
ing the cutting of an inch course over the arch. 

To do away with this cutting, arches in these and 
similar cases may, while maintaining the same bond¬ 
ing on the face, be increased in depth, care being 
taken that the proportion between the stretcher, 
header, and closer is relatively the same. Thus, by 












ARCHES AND GAUGED WORK 125 


dividing the 15 in. in the latter case into seven (the 
number of closers in a stretcher, header and closer 
combined), then taking four of these for a stretcher, 
and two for a header, etc., the stretcher will be found 
to measure 8f in., the header 4f in., and the closer 
2\ in. 

Equilateral or Gothic iirch (Fig. 191).—Opening, 3 ft.; 
face, 9 in. Draw an indefinite base line, upon it erect 
a perpendicular center line, and set out the opening 
AB half each side of it. With the point of the com¬ 
passes at A, and the pencil at B, draw the curve or 




half-intrados BC; then with the point at B and pencil 
at A, draw the other half AC. With the same radius 
points, and the compasses extended to 3 ft. 9 in., 
describe the outer line or extrados. When set out 
properly, this arch, unlike all other arches, has no 
key-brick, but a joint in the center. It will therefore 
be necessary, when pricking over, to allow half a course 
on each side of the center line, as though providing 
for a key-brick. If lines be drawn from A and B to 
C, it will be seen that each half of the arch is really a 
segment, and the template will be obtained in the 








126 


BRICKLAYERS’ GUIDE 


same way, only, where the courses meet on the center 
joint, these extra long bevels thus formed will have to 
be taken from the drawing and marked on the 
template. 

The above is not only the correct method for setting 
out the Gothic arch, but is also the strongest, as the 
courses are normals to the curve. But many object to 
keying, as it is called, with a joint, and insist upon 
having a key-brick. In the latter case (Fig. 192), the 
arch has to be set out, as all other arches, starting with 
half a course each side of the center line, and then 



pricking over to the springing. The approximate key, 
which is cut as a bird’s mouth, is then filled in from 
the center of the base line, and the approximate tem¬ 
plate obtained and traversed until it is accurate. The 
courses are then filled in with the latter. Under these 
new conditions, the courses, not being normals to the 
curve, will all differ in length and bevel. These will 
be obtained and marked on the template, in the same 
way as in the camber (Fig. 185). 

The Modified Gothic (Fig. 193).—When the equilateral 
arch has to be reduced in height, by remembering that 




ARCHES AND GAUGED WORK 


127 


the two sides are two segments only, the setting out 
becomes very clear. Again, taking the 3-ft. opening 
and 9-in. face, set out the base and center lines and 
the opening AB. Upon the center line set up the 
reduced height DC; join AC and CB. Bisect AC and 
CB with lines square to them, and produce to the base 
line. Where these meet will be the radial points from 
which to fill in the sides, the template being obtained 
as in the equilateral ^rch (Fig. 191). This, like the 
Gothic arch, may be filled in from the center of the 
base line, forming a key-brick, the lengths and bevels 
differing for each course. 

Lastly, should the curves on AC and CB need modi¬ 
fying (Fig. 194), these may be brought down by treating 
them as segmental arches, constructing the base line, 
and marking the height of the curve upon the center 
line. Mouldings on these arches are a very simple 
matter, being treated, when filled in from the radial 
point, as the segment, and from the center, as the 
camber arch. In neither case is there the difficulty of 
the miter to meet. 

The Elliptical Arch.—There is no curve in arch cut¬ 
ting that requires more care than the ellipse, and there 
is no arch in which faulty setting out, or a cripple, as 
it is termed, is more easily detected, especially by the 
trained eye. First, let it be quite understood that it is 
impossible to set out the ellipse by means of the com¬ 
passes, though a very near approach may be obtained, 
when the rise has not to be taken into consideration, 
by the following methods: 

Case 1. Fig. 195; opening 3 ft.; face 9 in.—Lay 
down the base line with a center line drawn at right 
angles above and below it indefinitely and the opening 
AB half each side, as before. Divide the opening AB 


128 


BRICKLAYERS’ GUIDE 



into four parts in the points C, D, E. With the point 
of the compasses at C, and the pencil at A, describe 
an arc; then, with the same distance in the compasses, 
but with, the point A, cut this arc in F. Repeat this 

on the other side 
of the opening, and 
again cutting this 
arc in F. Through 
F and C, and F and 
E, draw lines meet¬ 
ing at the center line 
in G, and extended 
indefinitely above F. 
Then, with the point 
of the compasses at 
G and extended to 
F, describe the remainder of the curve, or intrados, 
from F to F. Now, going back to C, and the pencil 
extended 9 in. beyond A, describe the extrados ter¬ 
minating at the line FG. Re¬ 
peat this on the other side of 
the opening. Then, with the 
point at G, and the pencil ex¬ 
tended, draw the topmost part 
of the extrados. It will not be 
apparent that in between the 
lines GF there is a segment 
arch, the template for which 
will be obtained as in that arch; 
and that the other two portions 
are parts of a semicircular arch, and again the tem¬ 
plate will be obtained as for the latter arch. This is 
the strongest method of filling in, but the appearance 
of having two distinct shapes of bricks upon the 



Fig. 196. 














ARCHES AND GAUGED WORK 


I2Q 


by 


face is certainly objectionable. The difficulty may be 
overcome by filling in the arch the same as the cam¬ 
ber, or by pricking over the extrados and filling in 
from the center of the base line for the approximate 
key. The bevels and lengths, of course, will differ, 
but the bricks will be alike on the face (Fig. 196). 

Case 2. Fig. 197.—Another method of setting out 
of the compasses, with a given rise, the 
height of the rise 
bearing a liberal pro¬ 
portion to the open¬ 
ing. Set out the 3-ft. 
opening as before, 
calling it AB, and 
the 14-in. rise CD. 
Join DB; cut off CD 
from CB in the point 
d\ take the remain¬ 
der dB, and cut off 
Db from DB in the point b. Taking any distance 
in the compasses greater than half Bb, and with 
the point first at b, then 
at B describe arcs cutting 
each other above and be¬ 
low bB. Through these 
intersections draw a line 
cutting the base line in 
the point E and the center 
line in the point F; then 
measure from A, fixing a 
point, G, upon the base 
E, F, G, will be the radial 
the arch as before. 

Case 3. —Fig. 198 is the 




line similar to E. Then 
points from which to draw 

string method, answering 









130 


BRICKLAYERS’ GUIDE 



very well for rough elliptical arches which have to be 
covered with plaster. Set out the opening, or major 
axis, AB, and the center, or half minor axis, CD. 
Taking the distance CA in the compasses, with the 
point at D, cut the base line at F and G. Then, hav¬ 
ing fixed pins at F, D, G, 
tie the end of a piece of 
string or thin wire at F, 
pass it round D, and tie 
at G. Remove the pin 
D, insert a pencil in the 
loop, and, with the string 
or wire extended as far 
as it will go, describe the 
curve. 

Case 4 .—Neither of the 
above, though useful in their way, can be compared to 
the trammel, which is the best practical method to be 
recommended to brick layers. (Figs. 199 and 200). 

Set out the opening AB upon the base line half each 
side of the center line 
CD, which will be 
drawn indefinitely be¬ 
low as well as above 
the base line. Prepare 
a square, the sides be¬ 
ing about 2-in. wide 
and Yz- in. thick, with 
a slight bevel taken off the under side of the outer 
edges; fix the square, the edge of one side coinciding 
with the center line, but below the base line, and 
the other with the right hand, and answering to the 
half of the base line. Next take a rod (which will 
be known as a trammel rod) with fixed pencil point; 



Q'Gaiwe 

r fbrcxtmao9 













ARCHES AND GAUGED WORK 


131 


measuring along the rod from the pencil point, 
fix a screw, with the head downwards, at a distance 
equal to the rise CD. Again measuring from the 
pencil point, fix a similar screw equal to the distance 
CB, i.e , half the opening. Now take some thin 
boarding, kept together by ledges, equal to rather 
more than half the opening in length, and more than 
the height of the rise in width, with the bottom and 
left-end edges answering to the right-hand side of the 
base and center lines, shot true and square to each 
other. Fix the mould in position, with the bottom 
and end edges coinciding with the center and right- 
hand half of the base lines. Then, with the trammel 
rod, the head of one screw working horizontally under 
the bevel along the top edge of the square, and the 
other vertically up the square, describe half the soffit 
upon the roughly prepared mould, which should be 
properly and truly cut to the curve. This may be 
termed the master mould. Practice only will give 
perfection in striking this curve. 

It is impossible to attach too much importance to 
the use of the master mould. The brick-cutter should 
set out his work to it, and also take the tickings upon 
it for the center; the carpenter should use it as his 
mould for making the center; and then it should be 
sent to the joiner’s shop, for the purpose of setting 
out the curve for the head of the frame. Lamentable 
results have occurred through these three trades work¬ 
ing independently. 

In setting out the arch, Fig. 200, the mould should 
be fixed in position, the bottom of it to the base line 
and the end to the center line; then, having drawn the 
intrados line, a gauge the required depth of the face 
should be cut, and while one end is worked round the 


132 


BRICKLAYERS’ GUIDE 


master mould, the other, having a pencil attached, will 
describe the other curve, or extrados. The template 
may then be obtained and the arch filled in as before. 
It will be seen from the description that theory differs 
in many points from practice. The extrados in theory 
is not parallel to the intrados. In theory also, each 
face course, or voussoir, being normals to the curve, 
would differ in shape, and, though not quite impos¬ 
sible, would be most expensive in practice. 

In setting out elliptical arches consisting of alternate 
blocks of brick and stone, the divisions should be in 



the proportion of 5 to 3 or 6 to 4 respectively; and in 
large arches each division should be set out normal to 
the curve, and separate templates obtained for each 
block of brick and stone. For instance, take an arch 
for a 7-ft. opening, 2-ft. 3-in. rise, 12-in. on the face 
(Fig. 201), to be filled in with red bricks and cut stone, 
but starting with red brick and keying in with stone. 
Set out the opening in either of the ways as shown, 
then upon the extrados, set out the courses of brick 
and stone, either as 5 to 3 or 6 to 4, whichever comes 
in most conveniently. In this case 5 and 3 appear to 
work in the best; so, starting with the key, tick in 











ARCHES AND GAUGED WORK 


133 


stone equal to three courses of brick, next to this five 
courses of brick, then stone, and so on. Number the 
divisions 1, 2, 3, 4, 5. Now find the foci to the outer 
curve. This is done by taking the distance CB in the 
compasses, placing the point of it at D, and cutting 
the base line in F and G. From tick 1 on the 
extrados draw lines to F and G, bisect the angle thus 
formed, and the bisector will be one of the joints 
required. Serve the other joints in the same way, and 
then get the templates for each division of brick. 




It would be as well, too, in large elliptical arches, 
say for 12-ft. openings, built of brick only, to make 
divisions in this manner, and obtain templates for each; 
for only those who have anything to do with these 
arches know the difficulty of obtaining one or even two 
templates for a very large ellipse. 

The scheme arch, Fig. 202, is one which, while 
starting off a level bed, has a less rise than a semi¬ 
circular arch. Let AB be the opening, with the center 
line CD, CD being also the 12-in. rise. Obtain the 
curve ADB as if for a segment, then extend the com¬ 
passes for the 9-in. extrados, carrying it down to the 






134 


BRICKLAYERS’ GUIDE 


springing line. Prick over the extrados, putting in 
the approximate key from the center C, and traversing 
the template until it comes out to the springing line. 
It will be noticed that the courses differ somewhat in 
bevel and length and must be taken off as in the 
camber. 

Bull’s Eye Arch, Fig. 203.—The curve of this arch is 
a complete circle, AB and CD being the base and 
center lines crossing each other at right angles, the 
curve and face being drawn and the template obtained 
as described in the construction of the semi-arch; the 
only difference is in the disposition of the two side 
key-bricks, which are placed as E and F. 

The above are the principal arches, but there are 
various others which are often used as a mixture of 
two of the foregoing, and are as follows: 

The Semi-Gothic, Fig. 204, has a semicircular intra- 
dos, but a Gothic extrados. Let AB be a 3-ft. open¬ 
ing, with CD as the center line. Set out the ordinary 
semi; then upon the base line beyond A and B measure 
off the face, say 9 in., and with either of the methods 
described for drawing the Gothic, proceed to draw the 
extrados according to the height required. In this 
instance the radius is taken from E and F. It will 
now be necessary to prick over the soffit of the arch to 
get the approximate key, putting in a trial key first to 
ascertain how the brick will hold out towards the top. 
Having fixed the approximate key, get the template as 
previously shown. The soffit bevels will be the ordi¬ 
nary semi-bevel, but the extrados bevels will all differ 
as will the length of the courses. When drawing the 
arch only, fill in from the center C. 

The Ellipse Gothic Arch, Figs. 204 and 206.—Let AB 
be the 3-ft. opening, 1 ft. 6 in. of which is each side 


ARCHES AND GAUGED WORK 


*35 


of the center line, and rise CD. Divide AB into three 
equal parts in E and F. From E and F, with the 
radius FB and EA, describe arcs as in the ellipse 
struck with the compasses, terminating at the points 
H and G. Join HD 
and GD by faint 2 ° 4 ‘ 

lines. From H and 
G through F and E 
draw faint, indefinite 
lines. Bisect HD 
and GD, and produce 
lines square to these. 

The points in which 
these latter lines 
meet the lines pass¬ 
ing through HF and 
GE will be the radial 
points for the top 
part of the arch. 

The extrados will be 
drawn by extending 
the compasses from 
the radial points by 
which the intrados is 
struck. Two tem¬ 
plates will be used, 
one answering for 
the two arcs, and the 
other for the two 
segmental portions 
of the arch. 

The Horse-Shoe or Moorish Arch, Fig. 205.—This is an 
arch but very seldom seen, but it is well that the prac¬ 
tical man should be acquainted with it. Set out the 













1 36 


BRICKLAYERS’ GUIDE 


3-ft. opening AB, and the center line and 3-ft. 3-in. 
rise CD. Join AD and BD; bisect DB; set up the rise 
and describe the curve as in the ordinary segmental 
arch; from the radial point E, through B, draw the 
skewback BG; measure the face upon BG; extend the 

compasses, and draw 


Fig. 206. 



Fig. 207. 


the extrados, terminat¬ 
ing at the opposite end 
of G upon the produced 
center line CD. Treat 
the other side of the 
arch in the same way. 
Although filling in the 
arch as though there 
were two segments is 
far stronger, still a 
better appearance is 
gained by pricking over 
the extrados, filling in 
the bird’s-mouth key 
from a point made by 
the skewback being 
produced to cut the 
center line, and then 
traversing the template, 
and treating the arch as 
a scheme. The courses 
will have different bev¬ 
els, and will be slightly 
different in length. 


The Ogee, Fig. 207, is another peculiar arch, weak in 
construction, and to be used only as an ornamental 
feature. Let AB be out to out of extrados, and CD 
the rise of the same. Draw a line from A to D, and 








ARCHES AND GAUGED WORK 137 

bisect it in E. Bisect DE, producing the center line 
both above and below it, as in the segment, and the 
same with EA. Upon DE set up the rise upon that 
part of the center line pointing to DB, and upon EA 
set up the rise upon the opposite side. Then describe 
the curves DFE, EGA, in the ordinary way. From 
the point H, by extending the compasses 9 in., put in 
that portion of the intrados from the line El to the 
center line CD, and from the point I, by decreasing 
the distance in the compasses 9 in., draw in the part 
of the intrados from El to the base line AB. Deal 
with the bottom portion of the ogee as a scheme, by 
getting the shape of the template from the point X, 
made by El cut¬ 
ting the base line; 
and the top part 
as a segment, ob¬ 
taining the tem¬ 
plate from the 
point H. Traverse 
the templates, ac¬ 
curately fill in 
the courses, and 
mark the bevels 
and lengths. 

Arches Springing from the Same Pier, but Differing in 
Size. —It frequently occurs —in bays, for instance—that 
while there is one large opening in the middle, there 
may be a smaller one upon one or each side of it,"and 
that one skcwback of the large and one of the smaller 
arch will b" adjacent to each other upon the same pier. 
Adhering to the rules for skewback, the latter will 
be at different inclinations, thus presenting a most 
unsightly appearance. To overcome difficulties such 







138 


BRICKLAYERS’ GUIDE 


as these must be left to the judgment of the practical 
man. As an example, two camber arches, one for a 
4’ft. and the other for a 2-ft. opening, both 12 in. on 
the face, have skewbacks of 4 in. and 2 in. respectively 
upon the same pier. Here an average should be 
struck, giving each arch a skewback of 3 in. 

As another distance, let there be two segment 
arches, one opening 4 ft. and the other 2 ft., both of 
■the same rise. In this case the smaller arch should be 
sacrificed to the larger, keeping the same rise in both, 
but giving the smaller the same skewback as the larger, 
thus converting it into a scheme. 

Intersection of Haunches. —When two arches spring 
from the same pier, and the depth of their combined 
faces more than equals the width of the pier, then a 
proper intersection of their haunches should be 
arranged. In Fig. 208, two semicircular arches, 14 in. 
upon the face, spring from an 18-in. pier. The bond 
on the faces is kept, as far as possible, down to the 
springing. But where the outer lines of the haunches 
meet, the intersection is alternated with saddle-bricks, 
1,2, 3, 4, and upright joints. Moulds will have to be 
procured with which to cut the saddle-bricks. 

It will be seen that it is impossible to get the saddle- 
brick No. 4 out of a brick flat, but it may be obtained 
by placing the brick on edge, which in this and other 
similar cases is permissible, the difference being made 
up by filling in at the back 

THE NICHE 

For years past, to cut and set a niche ha been con¬ 
sidered a clever achievement indeed; but, as a matter 
of fact, it is really not so difficult as it appears. By 
careful attention to directions and rules here given, 


THE NICHE 


139 


any practical man of ordinary ability will be able to 
accomplish it. 

Semicircular Niche. —That is to say, semicircular both 
on plan and on elevation, Fig. 209. First to set out 

and cut the body, taking the opening as 3 ft. Draw 

the opening AB, and at right angles to it the center 
line DC. From the center D, with DA as radius, 
describe the semi ACB, then extending the compasses 
4)4 in., put the 4)4-in. thickness of work in the 

body of the niche. Taking 2)4 in., or, if necessary, 

2)4 in. full in the compasses, prick over from C to A, 
but on the outer curve, as many 2)4 in. as will make 



an even number of stretchers and a half, so that half a 
stretcher shall come each side of the center line. 
Then with 2% in. again in the compasses, prick over 
the side CB, putting in the headers and closers to bond 
with the stretchers on the side CA. The first header 
at B will appear as a stretcher upon the face, and the 
first stretcher at A as a header, having a closer next it. 
Moulds must now be cut for the stretcher acting as 
face header at A, for the stretcher E, for the headers 
acting as face stretcher at B, for the closer F, and the 
bat headers G. 

The mode of preparing the moulds is as follows : 











BRICKLAYERS’ GUIDE 


*40 

Taking the stretcher E as an example, produce the 
joints XX, take two pieces of board, 10 x 4^ x y 2 in., 
screwed together, and having one edge shot. Fix the 
boards down over E with the shot edge from X to X. 
With the radius DC, and from the center D, describe 
upon them the inner curve. Then with a straight-edge 
from D to the produced lines X, draw in the radii, but 
allowing rather more than in. for joint and tinnec 
edges to the mould. Have the mould accurately cut 
and fitted to the lines, and after tinning they will be 
ready for use (Fig. 210). They are fixed in a box with 
the edges which were placed at XX downwards. The 
bricks are prepared by being properly bedded, and 
one face roughly squared; they are placed in the cut¬ 
ting box, two 
at a time, the 
roughly squared 
face down¬ 
wards, with the 
beds tight up to 
the moulds and 
fixed. The two 
ends and two 
faces are sawed 
completely 
over, and fin¬ 
ished with a file. Then, having been tested for accu¬ 
racy by squaring from the bed to face and ends, they 
are brought to thickness, and are then ready for the 
body of the niche. The other moulds and bricks 
will be prepared in the same way. In setting, the 
plumb rule, level, and a hand mould answering to 
the semi ACB, are all that will be required to keep 
the work true. It should also be tried occasion 





THE NICHE 


l4l 


ally, to see that the work is kept to the proper height. 

Next to set out and cut the head or hood, Fig. 211. 
Draw the base line AB, and set up the center line DC. 
With the point of the compasses at D, and the radius 
DB, describe the extrados ACB. Then, with the com¬ 
passes decreased, draw in the 9-in. face. Prick ovei 
the extrados as directed in other arches, putting in the 
approximate key, and obtain the template, which, 
unlike that for other arches, will extend from above 
the outer face to the point D. Having obtained the 
accurate template, place it in position as the key, and 
with its point at D. Then with the point of the com¬ 
passes at D, and the pencil extended to where the 



the courses extend from and include the face, home to 
the boss. Obtain the bevel and the cutting mark as 
though for the ordinary semi or face arch. 

Now take the courses as prepared for the body of 
the niche; half a course will answer for the right-hand 
side of the arch, and half for the left; but, instead of 


142 


BRICKLAYERS’ GUIDE 


squaring from the bed to the inside face, use the arch 
bevel, and bevel from the bed to the face, rubbing the 
bed to make it answer the bevel, and also the squared 
ends. 

The radiating box is now necessary, and is prepared 
as follows: Make a stout bottom 2 in. in thickness, 
in length about 2 ft. 6 in., i.e., somewhat longer than 
the template, the width being 2 ft. 3 in., or DC of the 
body plus 4^ in. thickness of work, with a little to 
clear. For the sides of the box, take two pieces of 
board 2 ft. 6 in, long and 4 in. wide, properly shot and 
tinned on the top edge. Upon the 
face of one of these boards tack the 
template, with the cutting 
edge of the latter flush 
with the tinned edge of 
the former. In this posi¬ 
tion the prepared side 
will project below the template, and with the bed of 
the template resting upon the bed of the bottom of the 
box. Securely nail it there. Scribe the cutting mark 
upon the tinned edge and remove the template. Go 
through the same process for the other side, taking 
care that the cutting marks on both sides are imme¬ 
diately over a line squared across the tail of the box, 
and the radiating box will be complete, (Fig. 212). 

Mode of Cutting.—Of the prepared courses, place the 
brick which answers to the face stretcher, or long 
header B of the body, in the box, with the face to the 
right-hand or A side of the box, and the soffit to the 
cutting mark, and, measuring away from the soffit of 
this brick at the cutting mark, and along the side of 
the box for the radial point D, describe the quadrant 
BCD. Place the remainder of the course to this 


» 

Fig. 214. 





THE NICHE 


M3 


curve; fix it down; then, keeping the wire saw at right 
angles to the sides of the box, saw the course right 
over, and keeping the file in the same position, prop¬ 
erly finish it, working away from the edge so as to pre¬ 
serve the arris. With the opposite hand go through 
a similar proceeding, and the same with the next 
courses. Cut the solid boss, and the hood will be 
ready for fixing. 

Fixing or Setting. —A solid head or turning piece is 
not at all necessary. In fact, when using this, the 
most important part of the work, which when finished 
will be seen, has to be guessed at while fixing. 
Instead of this, a hollow semicircular rib to fit the 
head or body should be made, having an outside rib 
only, about y 2 in. thick, so that while the setting pro¬ 
ceeds the inside may be seen. Upon this will be 
marked from the drawing the soffit joints of the face 
arch, so as to ensure that the work is rising properly. 
Then, starting upon each side, proceed to fix the work. 
If the front turning piece should be found insufficient 
when nearing the key, then a lesser but similar semi¬ 
circular mould may be used further in. Finally prop¬ 
erly grout in the work with Portland cement. 

The Elliptical Niche. —This is similar to the semi¬ 
circular but elliptical upon plan. Taking the opening 
as 3 ft., set out the body upon plan, using the trammel 
method. Fill in the stretching and heading courses 
as before, but in this case pricking over the outer and 
inner curves for the proper shape of the bricks, and 
obtain the moulds as already directed. The head will 
be semicircular and, although the body is elliptical, 
there will be but one bevel, the courses being placed 
in the box, not to a quadrant, but to the shape of half 
the elliptical curve. 


144 


BRICKLAYERS’ GUIDE 


Moulded Soffit to Niches.— It will be readily seen that, 
should the edges of the opening and the soffit of the 
arch be moulded, this would be cut on the moulds 
answering to the bricks A and B, Fig. 209, and would 
be cut upon these bricks at the same time that they 
were being shaped for the niche. 

LABELS TO ARCHES AND NICHES 

Moulded labels going over camber arches need very 
little description, being merely moulded bricks as 
stretchers or headers set over the arch. But when a 
label has to be fixed over a semicircular or segmental 
arch or niche, it is very evident that if straight moulded 
bricks were run over such arches, their beds would 
appear as a series of short straight lines, looking most 
unsightly. It is, therefore, apparent that a curve 
struck with the same radius with which the arch was 
set out must be run on each, and they will also have to 
be cut to a radial template, in a similar way to an arch; 
the course, 3 in. or 4^ in. in depth, as the case may 
be, being set on the top of the arch. If it be 3 in. 
deep, then the pricking over on the extrados will be 
4^ in. 

The bricks will be moulded one at a time. The 
mode of doing this is to use a pair of clip moulds, 
which will hang one on each side of the brick (Fig. 
213), placed in the box, bed or soffit upwards; then, 
after sawing and roughly filling it, the brick should be 
finished off with a piece of stout sheet iron having a 
convex curve of the same sweep as the extrados of the 
arch worked upon it (Fig. 214). By keeping the sheet 
iron upright while using it, the curve will be worked 
not only upon the soffit of the brick, but throughout 
the moulding. After the label has been set/sufficient 


THE ORIEL WINDOW 


145 


substance will have been left upon the top edge of the 
label to admit of its being worked off with a hand- 
stone, either to the eye or to a prepared mould. 

THE ORIEL WINDOW 

The oriel window, whether in stone or brick, is a 
most artistic feature in a building. Stone lends itself 
more readily to the safe carrying out of this work than 
brick. When built of the 
latter material, a frame of 
light ironwork treated with 
oil or painted to prevent 
oxidation may be constructed, 
with the ends either built into 
the main wall, or bolted firmly 
to the joists. But, according 
to circumstances, so the mode 
of keeping the work in its place 
must be determined by the 
practical man. 

To cut the oriel, set it up in 
elevation equally each side of 
a center line. Now, if the 
courses are to be equal in thickness, the center line, 
or height, must be divided 
off into 3-in. courses. The 
courses will then appear upon 
the curve as unequal in thick¬ 
ness. But if they are to ap¬ 
pear equal in thickness, prick 
round the curve at 3 in. The 
courses will then really be 
unequal (Fig. 215, in which the setting out is accord* 
ing to the latter system). Set out a pair of moulds for 



Fig. 216. 



template 


Fig. 215. 














146 


BRICKLAYERS’ GUIDE 


each course, with the curve worked upon each. Draw 
a horizontal line beneath the elevation, and from each 
course upon the curvature of the latter, drop perpen¬ 
diculars to the horizontal line. Then from the center 
to each of these points will be the radius with which to 
draw the plan of each course. Prick round the outer 
curve and obtain the template, which must reach from 
the outer line to the radial point. Different cutting 
marks will be placed upon the template for each 
course, working from the outer one towards the radial 
point (Fig. 216). From this plan it will be seen how 
many bricks will be wanted for each course. To cut 
the work, bed the bricks, square one face, and mould 
and take to thickness at the same time. Then place 
them in the radial box at the cutting mark to which 
they belong, and after sawing and finishing with the 
file, they are ready for setting. 

In setting, take care to half-bond the courses and 
properly flush up with Portland cement. An inverse 
mould fixed at each end, and ribs or moulds answering 
to different courses upon plan, will be found useful to 
test the work as it proceeds. 

MEASUREMENT OF BRICKWORK, POINTING, ETC. 

Most bricklayers know how to use the foot rule in 
measuring ordinary work, but, having attained the 
measurement, the difficulty arises as to how to square 
or cube the quantities thus obtained. • Another diffi¬ 
culty also met with is how to take the measurement of 
awkward shapes, e.g., gables, arches, etc. This chap¬ 
ter, therefore, is intended to help those who have no 
knowledge whatever of the subject. 

In the building trades, measurements are taken iis 
foot run, foot super, or square and foot cube. 


MEASUREMENT OF BRICKWORK 147 

Foot Run relates to length only; for instance, drains, 
tile-creasing, cutting under 6-in. wide over circular 
arches, cement fillets, etc., are taken and priced at the 
foot ruk. In this there are 12 in. to a foot, and 3 ft. 
to a yard. 

Foot Super, or Square.— Here length is multiplied by 
width or height; a paved floor, so many feet long by 
so many feet wide, will have so many feet super, or 
square, of paving. In a square foot there are 144 

square inches. 
To make sure that 
this is so, draw a 
square 12 in. long 
by 12 in. wide, 
and divide up into 
inches; it will be 
seen that there are 
144. But in the 
building trades, 
both with square 
and cube measure¬ 
ments, twelfths of 
feet are reckoned 
upon. So 6 square 
feet 72 square 
inches would be 
written 6' 6" super. There are also 9 square feet in a 
square yard. This may be proven by laying down a 
square 3 ft. long by 3 ft. wide, and dividing into 
squares 12 in. by 12 in., when nine squares will have 
been formed Foot super is used in measuring facings, 
paving, tiling, etc. 

Cube measurement is length x (multiplied by) thick¬ 
ness x depth or height. Thus, in finding the cubic 




























148 


BRICKLAYERS’ GUIDE 


contents of an 18-in. square pier, say 6 ft. high, it 
would be stated as 6' x i' 6" x i' 6". In the cubic foot 
it will be seen (Fig. 217) that there are 1728 cubic 
inches. That is to say, that 1728 wooden cubes, 
1 x I x I in. maybe built up to form a cube 12 in. long, 
12 in. broad, and 12 in. deep. Here again, instead of 
reckoning 1728 inches, the cubic foot is divided into 
twelve cubes, and 6 cubic feet 864 cubic inches is 
written as 6' 6" cube. There are 27 cubic feet in a 
cubic yard, as may be seen by making twenty-seven 
cubes 12 x 12 x 12 in. and piling them together to form 
a cube 3x3x3 ft. Cubic measurement is used for 
excavations, concrete, etc. 

Before squaring dimensions, a perfect mastery of the 
multiplication tables up to 12 times is necessary. A 
thorough knowledge of these tables will also be suffi¬ 
cient for division when needed. Thus, knowing that 
12 times 9 are 108, then 12 into 108 equals 9, and 12 
into 112 equals 9 and 4 over, or 9 into 108 equals 12, 
and 9 into 112 equals 12 and 4 over, etc. A con¬ 
stant practice in this will be invaluable in squaring 
dimensions. 

There are several arithmetical methods of squaring 
dimensions, but for those who are not expert it would 
be better to adopt one system only. An easy and 
accurate method is that known as cross multiplication, 
or duodecimals. By duodecimal is meant multiplica* 
Hon by twelves. Take as an instance 5 ft. 7 in. x 2 ft 
4 in., or, as it is written 



11' 2" 

T10" 4" 

Wo r/ T 7 




MEASUREMENT OF BRICKWORK 149 


Here start to multiply 5 ft. 7 in. by the 2 ft. and say 
twice 7 are 14; 12 into 14 equals 1 and 2 over; place 
the 2 under the 4, and carry 1. Next, twice 5 are 10, 
and the I carried equals 11; place this under the 2 ft. 
Proceed with the multiplication by 4 in., and say 4 
times .7 are 28; 12 into 28 equals 2 and 4 over; place 
the 4 in the line under 11 ft. 2 in., but one place to the 
right of the 2 in., and carry the 2. Then 4 times 5 are 
20, and the 2 carried make 22; 12 into 22 equals 1 and 
10 over; place the 10 under the 2 in. and 1 under 11 ft. 
Add these two lines, starting with the first figure to 
the right; so 4, with nothing added, equals 4, bring it 
down in its place; 10 and 2 (or 10 plus 2) are 12; 12 
into 12 equals I and none over, place o under the 10, 
and carry 1; the 1 carried plus 1 and n are 13, place 
the 13 under the 1; and the answer will be 13 ft. 
Whenever in the place twice removed to the right of 
the feet (or where 4 appears in the last result) the fig¬ 
ure is 6 or over, reckon this as one more to the place 
to the right of the feet (or where o appears in the 
last result), but when under 6 discard it. Thus, if the 
last answer had been 13' o" 7" call it 13' 1", but being 
13' 0" 4" only, it should be taken as 13'. 

Cubing. —Let 6 ft. 4 in. x 2 ft. n in. x 3 ft. 6 in. be 
the dimensions, written as 

6 ' 4 " 

2' 11" 

- 3 ' 6" 


Proceeding as before (see below), begin by multiply¬ 
ing 6 ft. 4 in. x 2 ft. and say twice 4 are 8; this cannot 
be divided by 12, so place it under the 11. Twice 6 are 
12; place this under the 2 ft. Then multiply by the 



50 


BRICKLAYERS’ GUIDE 


ii in.; ii times 4 are 44; 12 into 44 equals 3 and 8 
over; place the 8 under the 12 ft. 8 in. but one place 
to the r*ight of 8, and carry the 3. Then 11 times 6 are 
66, and the 3 carried make 69; 12 into 69 equals 5 and 
9 over. Place the 9 under the 8, the 5 under the 12, 
and add the two lines; 8 and oequals 8, write it in its 
place under the 8; 9 and 8 are 17, 12 into 17 equals I 
and 5 over, place the 5 under the 9 ft. and carry the 
1; 1 and 5 are 6, and 12 are 18 ft., place the 18 in its 
proper position as feet; and the result so far is 18' 5" 
and 8". Multiply this by 3 ft. 6 in. placing the 3 
under the 18, and the 6 under the 5. As before, first 
multiply by the feet and say 3 times 8 equals 24; 12 
into 24 equals 2; carry the 2 and place 0 in the lines 
under the 3 ft. 6 in., but to the right of the 6. 3 times 

5 equals 15, and 2 equals 17; 12 into 17 equals I and 5 
over; place the 5 under the 6 and carry 1. 3 times 8 

are 24, and the 1 carried makes 25; place the 5 under 
the 3 and carry 2. 3 times 1 are 3 and 2 equals 5; 

place it to the left of the last 5, making 55. Then 
multiply by the 6 in. and say 6 times 8 are 48; 12 into 
48 equals 4 and o over; again place the o under the 
55' 5" o, but one place to the right of the o, and carry 
the 4. 6 times 5 are 30, and the 4 carried, 34; 12 into 

34 equals 2 and 10 over; place the 10 under the o and 
carry 2. Then multiply 18 by 6, adding on the 2, and 
making no; 12 into no equals 9 and 2 over, place the 
2 under the 5, and the 9 under the right hand 5 of the 
55. Add the two lines together; o coming first, bring 
down; 10 and 0 are 10, bring down the 10; 2 and 5 are 
7, bring this down; 9 and 5 are 14, put down the 4 and 
carry the 1; 1 and 5 are 6, put the 6 to the left of the 4. 
The answer is 64' 7" 10" cube or 64' 8" cube. Divid¬ 
ing this by 27, we get 2 yards 10' 8" cub~ 


MEASUREMENT OF BRICKWORK 151 


6' 

4" 

2 f 

11" 

12' 

8" 


5' 

9" 

8" 

00^ 00 

5" 

6" 

8" 

55' 

5" 

10" 

9 ' 

2" 

10" 0" 

64' 

7 " 

10" 0" 


Timesing.— When a dimension occurs several times 
over, it is written thus— 



which means that the result of 5 ft. 7 in. x 2 ft. 4 in 
is to be multiplied by 2; and looking to rules given 
it will be seen that this is 13 ft. x 2, which is 26 ft. 
Again, a quantity written thus— 

3.2I5' 7" 

1 2' 4" 

or dotting on, it is called, means that the result of 5 ft. 
7 in. x 2 ft. 4 in. is to be multiplied by 2 added to 3 or 
5; and the whole result would be 65 ft. 

Digging is taken at the yard cube, and depends for 
price upon the depth, and the distance the earth has 
to be wheeled or carted. 

The least amount of depth of trench for a 14-in. 
wall, including footings and concrete, would be 2 ft. 
3 in.; the width being 3 ft. 3 in. Then, taking it that 
the measurements of digging to trench for a 14-in. 
wall 20 ft. long are required, the trench itself would 
be 20 ft. plus (3' 3" — 1' 2") equals 22 ft. 1 in. x 3 ft. 
3 in. x 2 ft. 3 in. The 2 ft. I in. being projection of 






>52 


BRICKLAYERS’ GUIDE 


footings, concrete, etc., at each end; and the amount 
of concrete 22 ft. 1 in. x 3 ft. 3 in. x I ft. 3 in. These 
dimensions may be obtained by drawing the plan of 
the footings and concrete for length and width, and 
setting up the section for depth, as already shown on 
page 8. 

Concrete of less thickness than 12 in. or where under 
pavings, etc., is taken at per yard super. 

In brickwork the difficulties of measuring are some¬ 
what greater. In some places practice is to reduce all 
work of iy 2 bricks thick and upwards to a standard of 
272 ft. super i x /2 bricks thick, which is called a rod; 
the actual measurements being 16% ft. x 16% ft. x i}£ 
in., or 306.2812 cu. ft., reckoned in practice as 306 cu. 
ft Walls under this thickness are generally specified 
with the work they entail, e.g., struck joints both 
sides, pointed, circular, etc. When measuring foot¬ 
ings, for instance, multiply the average length by the 
average thickness, and then by the height. When 
taking the average thickness, first add the width of the 
top course to the width of the bottom course in bricks, 
and divide by 2; thus for a 2-brick wall,.2 plus 4 + 2 
equals 3. Then the average thickness will be 3 bricks, 
or 2 ft. 3 in. (When the bottom course is doubled, 
take one of these courses separately, and afterwards 
add.) Taking the length of the wall to be 20 ft., the 
average length of the footings will be 20 ft. plus (2 ft. 
3 in. average thickness — 1 ft. 6 in. width of neat 
work) equals 20 ft. 9 in. The height of the footings, 
as already shown, including one course of the wall 
will be five courses, or 15 in c , and the quantity of foot¬ 
ings equals 20 ft. 9 in. x I ft. 3 in. 3 bricks thick equals 
25 ft. n in. or 26 ft. of work 3 bricks thick. By 
multiplying 26 ft. by 6 (the number of half bricks in 3 


MEASUREMENT OF BRICKWORK 153 

bricks) and dividing by 3 (the number of half bricks 
in l% bricks), the work will be brought to the standard 
measurement, 26 ft. x 6 3 =52 ft. 

In ascertaining the quantity of digging, to trenches, 
concrete, and footings, for a rectilineal building, 
much labor may be saved by taking an average. Let 
ABCD (Fig. 218) be the plan taken through the 
3-brick wall of a building 50 ft. x 30 ft. out to out. If 
miter line* be drawn from A to E, B to F, C to G, 


A _ * 3 ' 6 * _ * 3-6 * _ *3 6 * _ B 


V 

i 

i 

i 

( i 

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Fig. 218. 


and D to H, and lines midway between the inner and 
outer lines, but terminating upon the miter lines, be 
also drawn, the average length of the walls will be 
found to be 2/47 ft. 9 in. and 2/27 ft. 9 in. Then the dig¬ 
ging for trenches will be 2/47 ft. 9 in., or 151 ft. x 5 ft. 
6 in. x 3 ft. 10 in., which equals 3183 ft. 7 in. cube, or 
117 cu. yd. 25 cu, ft. Concrete 151 ft. x 5 ft. 6 in. x 1 
ft. 10 in. equals 1522 ft. 7 in. cube or 56 cu. yd. 11 cu. 
ft. Footings average thickness equals (3 plus 6) + 2 












154 


BRICKLAYERS’ GUIDE 


equals 4 y 2 bricks; the height including one course of 
wall equals 1 ft. 9 in., which equals 151 ft. x I ft. 9 in. 
x (9 half bricks + 3 half bricks or) 3 equals 792 ft. 9 
in. or 793 ft, super of reduced work. To this will be 
added one of the bottom doubled courses, which equals 
151 ft. x 3 in. x (12- 3 or) 4. This equals 151 ft. of 
reduced work, and together 793 ft. plus 151 ft. equals 
944 ft. or 3 rd. 128 ft. 

Brickwork is usually measured first as ordinary stock 
work, length by height, the thickness stated, extra per 
foot super being allowed for facings; and all openings, 
arches, etc., deducted. It is usual to measure floor 
by floor, starting from the footings to the under side 
of the ground floor joists, and so on. 

Taking Fig. 218 as a guide, and supposing the 
quantities of the wall AB 15 ft. in height, faced with 
red builders and pointed, with a weather joint, and 
containing the three 6 ft. x 3 ft. 6 in. window openings, 
are required, the stock work will measure 50 ft. x 15 
ft. 3 bricks thick 750 ft. x (6-3) or 750 ft. x 2 equals 
1500 ft. reduced work. But from this must be de¬ 
ducted (3/3 ft. 6 in. x 6 ft.) plus (3/4 ft. 3 in. x 6 ft.) 1 y 2 
bricks thick equals 139 ft. 6 in. 1500 ft. — 139 ft. 6 
in., equals 1362 ft. 6 in. or 5 rd. 2 ft. 

The extra for facings, including pointing, will be 
50 ft. x 15 ft. super, and added to this six reveals 6 ft. 
x 14 in., and three soffits of arches, say, allowing for 
rise, 4 ft. 14 in. From this again will be deducted 
the superficial measurement of the three window open¬ 
ings; 50 ft. x 15 ft. equals 750 ft.; 6/6 ft. x 1 ft. 2 in. 
equals 42 ft.; 3/4 ft. x I ft. 2 in. equals 6 ft.; together 
750 plus 42 ft. plus 6 ft. equals 798 super; deduct 3/6 
ft. x 3 ft. 6 in. equals 63 ft. super; leaving 798 ft. — 63 
ft or 753 super. 


MEASUREMENT OF BRICKWORK 155 


Chimney Breasts.—Measure the width by the height, 
stating the thickness of the work; deduct the fireplace 
opening. The flues are taken in as if solid, pargeting 
to these being numbered. Ovens and coppers are 
also measured as solid, deducting the ash-hole only. 

Arches.—The face and soffit are measured separately, 
and afterward added. The camber arch (Fig. 185) 
will serve as an example for measuring. The opening 
being 3 ft., but taking 12 in. as depth of face, add one 
skewback, making it 3 ft. 3 in. x 12 in. (depth of face), 
3 ft. x 4^ in. soffit; the superficial measurement in 
this case will then be 4 ft. 4 y 2 in. 

For all radial arches, pass the tape round the face, 
midway between the intrados and extrados, arrive at 
the amount, and multiply by the depth of the face; 
then serve the soffit in a similar manner, multiplying 
by the depth. 

Taking Fig. 176 as an example, the face is found to 
measure 3 ft 9 in. x 12 in. equals 3 ft. 9 in., soffit 3 ft. 
2 in. x 4 y 2 in. equals I ft. 2 in. and together 4 ft. 11 in. 

The practical man sometimes finds a difficulty in 
multiplying by such awkward quantities as 6. ft. 9 in. 
434 in.; but, by a little thinking, these become quite 
easy. 

Feet multiplied by feet will give square feet, e.g., 
12 ft. x 12 ft. equals 144 ft. 

Feet multiplied by inches equal twelfths of feet; 
e.g., 20 ft. x 6 in. equals sq. ft.; inches multiplied 
by inches equal square inches. 

Feet multiplied by 6 in. will give half the amount 
multiplied; thus 12 ft. x 6 in. equals 6 ft. square. 

Feet multiplied by 3 in. will give one quarter of the 
amount multiplied; 12 ft. x 3 in. equals 3 ft. square. 

Feet multiplied by 9 in. will give the last two results 


156 


BRICKLAYERS’ GUIDE 


combined; 12 ft. x 9 in. equals of 12) equals 6, plus 
of 12) equals 3, together 9 ft. square. 

Feet multiplied by 4^ in. will first be taken as the 
last and half of that again taken, because 4^ in. is half 
of 9 in. 

Feet multiplied by 2% in. would be half of the 
above, for the same reason. 

Feet multiplied by 4 in. will give one-third of the 
amount multiplied, 4 in. being one-third of 12 in. 

Feet multiplied by 8 in. will give twice the result 
of the last, 8 in. being two-thirds of 12 in. 

To reduce cubic feet of brickwork to superficial feet 
of standard thickness, deduct one-ninth, e.g., 40 ft. x 20 
ft. three bricks thick equals 1600 ft. reduced work; 
compare with 40 ft. x 20 ft. x 2 ft. 3 in. equals 1800 cu. 
ft.; take from this one-ninth of 1800 ft. or 200 ft., leav¬ 
ing 1600 ft. reduced work as before. 

Practical men usually take pointing by the square of 
100 ft. super. 

To measure gables or pediments, take the central 
height by half the base for superficial measurement, 
and for brickwork according to the bricks thick. 

To find the area of a circular opening, multiply the 
square of the diameter by 0.7854; e.g., diameter of 
circle, 10 ft. 

10 ft. x 10 ft. equals 100 ft. x 0.7854 equals 78.54. 

To measure fair cutting to a circle, multiply the 
diameter by 3.1416; e.g., diameter of circle, 10 ft. 

10 ft. x 3.1416 equals 31.416. 

For a semicircular arch, half the above, e.g., diam¬ 
eter of semicircular arch, including depth of face on 
each side, equals 10 ft. Fair cutting round the arch 
equals 31.416 as above for the whole, - 2 equals 
15.708. 


MEASUREMENT OF BRICKWORK 157 


In measuring brickwork over 60 ft high from the 
ground, it should be kept separate, and divided into 
heights of 20 ft., viz., 60 to 80, 80 to 100, etc The 
reason for this is that the higher the work goes the 
more expensive it becomes to build. 

Keep the following work separate: 

Brickwork built overhand. 

Raising on old walls, stating the height the work 
commenced from ground level. 

Circular brickwork. 

Half-brick partition walls. 

Sleeper walls. 

Measure hollow walls as solid. 

The following work is usually taken at the yard 
super: Lime-whiting; pointing when not included 

with the facings; brick-nogging, including timbers, 
stating if built flat or on edge; cement floated face, 
stating thickness, if to falls, and if floated or troweled; 
all kinds of paving; wall tiling, giving full descriptions. 

Work measured by the foot super: Damp-proof 
courses; trimmer arches; fender walls; sleeper walls; 
half-brick partition walls; arches generally, except 
gauged; facings, keeping the different kinds separate. 

Work measured at per foot run: Cement filleting, 
cuttings under 6 in. wide, pointing flashings, cutting 
chases for pipes, brick on edge, and other kinds of 
copings. 

Items numbered: Bed and point frames; setting 
stoves and ranges, fixing chimney pots, ventilating 
bricks, parget and core flues, rough relieving arches. 

Hoop-iron bonding is measured at per yard run, 
adding 5 per cent to the length for laps, stating ii 
tarred and sanded, and making no deductions for 
opening's. 


BRICKLAYERS’ GUIDE 


158 

When finished estimating as above, add at least 7^ 
to 10 per cent to the whole amount for extra scaffold¬ 
ing, and contingencies generally. Some builders add 
as much as 15 or 20 per cent to estimate, but, when 
competition is sharp, the contractor adding this large 
percentage will stand a poor chance of securing the 
work.* 

TOOLS USED BY THE BRICKLAYER AND HIS 
HELPERS 

The tools shown in the Frontispiece (which see), 
figuring from 219 to 237 included, are used by the 
bricklayer and his helper. There are other tools also 
made use of that are not included in this list, such as 
the iron or steel square, various forms for shaping 
bricks, trestles, stands and other appliances for special 
work; but the ones shown cover the main ground. 
There is: 1, the pick for breaking up hard ground; 2, 
the grafting tool for digging out earth such as stiff 
clay; 3, the shovel; 4, the chalk line; 5, boning rod, 
for taking levels; 6, spirit level; 7, hod made to carry 
about 12 bricks, or ^ of a bushel of mortar; 8, a larry 
or hoe for mixing mortar; 9, the beedle or mall, is a 
large wood mallet with a circular pine head, with 
rounded ends about 18 in. long and 15 in. in diameter, 
with a handle about 3 ft. long. It is used by the pavior 
for punning paving stones into their position when 
bedding, as shown in Fig. 238; 10, the rammers are of 
two kinds—1st, that used for ramming granite sets in 
roadways, which consists of a cylindrical piece of wood 

♦Much of the foregoing matter has been taken from “Brick¬ 
laying and Brick-cutting/’ by H. W. Richards, a most excellent 
work. 




TOOLS USED BY BRICKLAYERS 159 


about 3 ft. 6 in. long, with a vertical handle at top and 
a horizontal handle about half-way up, as shown in 
Fig. 239; 2d, that used for the bottoms of trenches 
and for consolidating ground. They are of the shape 
shown in Fig. 240, the head being of iron and about 
10 lbs. in weight; the handle is of ash, about 10 ft. 
long. 

Bricklaying Tools.— 1, large trowel used for the 
spreading of mortar and the bedding of bricks; 2, the 
2-ft. rule; 3, the plumb-rule and bob for the carrying 



up of walls perpendicularly; 4, the short straight-edge, 
about 3 ft. in length, with the brick courses marked on 
it for the building up of corners; 5, the spirit level for 
testing the horizontality of work; 6, line and pins for 
building the portions of walls straight between corners. 
















i6o 


BRICKLAYERS' GUIDE 


Brick-cutting Tools.—Rough cutting: i, the large 
trowel; 2, the club hammer and bolster, for cutting 
with greater exactitude than with the trowel; 3, the 
cold chisel for the cutting of chases and for general 
work. 

Fair cutting, hard bricks: I, the tin saw for making 
an incision of an inch deep, preparatory to cutting 
with bolster; 2, the chopping block, which is an 
arrangement of two blocks of wood so fixed as to sup¬ 
port a brick in an angular position convenient for cut¬ 
ting; 3, the scutch consists of a stock and a blade, the 
latter generally formed of aflat file about 10 x 1 in., 
sharpened at both ends and fixed in the stock by means 
of a wedge. This displaces, and is an improvement on, 
the old brick axe, as the blade can be removed and 
sharpened readily; it is used to hack away the rough 
portions on the side of a brick after the edges have 
been cut by the tin saw and bolster. 

Fair cutting, soft bricks: 1, the saw consists of a 
frame holding the blade, which consists of twisted 
soft steel or malleable iron wire (No. 16 B.W.G.), and 
is used for cutting soft rubbing bricks; 2, the rubbing 
stone is a circular slab of gritty stone 20 in. in diam¬ 
eter, for rubbing the faces of bricks to a true surface; 
3, the mould is a wood box enclosing bricks that are 
to be cut to a shape, the sides of the box being formed 
to that shape, and the edge over which the saw blade 
works is protected by a strip of zinc; 4, the square, 
bevel, and compasses are used in the setting out of 
work. 

Pointing tools consist of: 1, small.trowels for filling 
up joints of new brickwork; 2, the pointing rule, which 
is a feather-edged straight-edge with two small pieces 

in. thick nailed at each end to keep the rule away 


BRICKLAYERS’ MORTAR 


161 


from the wall and allow the trimmings to fall through; 
3, the frenchman, for trimming joints, consists usually 
of an old table knife, with the end ground and turned 
up, as shown in plate; 4, the jointer, used for tuck 
pointing in old work. 

BRICKLAYER’S MORTAR 

Mortar. —The mortar is composed of one of lime to 
two or three parts of sand, or from one of Portland 
cement to one to four of sand. Lime mortar some¬ 
times has cement added to it to increase its strength 
and hasten its setting. 

Lime mortar should not be used when fresh nor in 
an untempered condition, as in that state its cohesive 
value is small and it is difficult to work; but after 
making should be left two days at least, then turned 
over and beaten up again. 

This tempering gives it the property of working 
evenly and fat. Cement mortar should be used as 
soon after making as possible, as the setting action 
commences immediately after mixing and any further 
working up of the mortar lowers its ultimate strength. 

Building During Frosty Weather.— All brickwork 
should be suspended during frosty weather, as its sta¬ 
bility is endangered by the disintegration of the mortar 
by the frost while it is wet. When the work is 
urgently required it should be carried up in cement 
mortar fn the intervals between the frost; but all the 
freshly built portions should be carefully covered and 
protected on any recurrence of the frost. 

Technical Terms. —Course is the name given to the 
row of bricks between two bed joints; the thickness is 
taken as one brick plus one mortar joint, in this work; 


BRICKLAYERS’ GUIDE 


162 

unless otherwise stated, it will be considered as 3 in., 
or, as technically described, four courses to the foot. 

It usually requires about l}i barrel of lime and 1 yd. 
of sand to make the mortar for 100 bricks, and one man 
with 1% tender will lay 1,500 to 2,000 bricks per day; 
that is, four masons and five helpers will lay about 8,000 
brick, but this should be reckoned on straight walls. 

The same proportions of sand and lime, or cement 
and lime, may be used also for masonry. 

Allow 12 bushels sand to one barrel. 

Allow about .0012 bushels fireclay for each 100 brick 
and 1 barrel of Portland cement to 800 brick. 

A load of mortar is equal to one cu. yd. It requires 
1 cu. yd. of sand and 9 bushels of lime; it will fill 30 
hods. 

A bricklayer’s hod measures 1 ft. 4 in. x 9 in., 
equals 1,296 cu. in. It holds 20 bricks and weighs 
about 113 lbs. when full. 

A single load of sand is equal to I cu. yd.; a double 
load, 2 cu. yd. A measure of lime is one load. 

One barrel of fire clay will make a thin mortar for 
1,000 bricks. 

One part cement to two parts sand for cement 
mortar. 

Mortar. —One part of lime to 3 or 3^ parts of sharp 
river sand; or 1 part of lime to 2 of sand and 1 of 
blacksmith’s ashes. 

Brown Mortar.— One-third lime, two-tmrds sand, and 
a small quantity of hair. This is for plastering. 

Coarse Mortar. —One part of lime to four of coarse 
gravelly sand. 

One rod of brickwork requires 1 cu. yd. of lime and 
3 i single loads of sand; or, 36 bushels of cement and 
36 bushels of sharp sand. 


BRICKLAYERS’ MORTAR 163 

One yard, or 9 superficial feet, \ x / 2 bricks thick, 
requires 2^ bushels of cement. 

One superficial yard of pointing brickwork in cement 
requires *4 of a bushel. 

Some kinds of cement set so fast that it is not safe 
to mix more than can be used within twenty minutes. 

Mortar made of cement, worked after it begins to 
set, becomes worthless. 

The following are the rules generally used by masons 
in figuring brickwork: 

Corners are not measured twice. 

Openings over two feet square are deducted. 

Arches are counted from the spring. 

Pillars are measured on the face only. 

To find the number of bricks in a wall. 

in. wall per superficial foot.... 7 bricks. 

9 in. wall per superficial foot.... 14 bricks. 

13 in. wall per superficial foot. . . .21 bricks. 

17 in. wall per superficial foot.. . .28 bricks. 

22 in. wall per superficial foot.. . .35 bricks. 

26 in. wall per superficial foot... .42 bricks. 

30 in. wall per superficial foot... .49 bricks. 

And seven bricks additional for every half brick 
added to the thickness of the wall. 

One foot superficial of gauged arches requires 10 
bricks. 

One thousand bricks closely stacked occupy about 
56 cu. ft. 

One thousand old bricks, clean and loosely stacked, 
occupy 72 cu. ft. 

Stock or place bricks generally measure 8 % x 4% > 
2 % in., and weigh from 5 to 10 pounds each. 



GENERAL SPECIFICATION CLAUSES 


MATERIALS 

BRICKS 

1. All bricks intended for use under this Specification must 
be the best of their respective kinds, hard, square, sound, well- 
burnt, and even in size. No brick must absorb more than one- 
sixth of its dry weight in water during one day’s immersion. 
Samples of each kind, selected at random from the load, must 
be deposited with and approved by the architect before any of 
that particular kind are laid. 

Note. —If the bricks are not specified from particular makers 
the following may be added to the foregoing clause: 

And the architect is to be informed from what manufacturers 
the bricks are being obtained, if he so desires. 

All bricks shall be carefully handed from the carts and stacked, 
and no broken bricks or bats are to be brought upon the ground. 

2. All hard, sound, clean, and approved old bricks, obtained 
from pulling down the old buildings on site, may be re-used 
where directed. 

3. The stock bricks are to be (obtained from.) 

or (equal to the manufacture of.) similar in all re¬ 

spects to the samples deposited with the architect. 

4. The stock bricks for facings are to be carefully selected for 
their evenness of color and face, and the visible arrises must be 
undamaged. 

5. The pressed (red) facing bricks are to be (obtained from 

.) or (equal to the manufacture of.) 

similar in all respects to the samples deposited with the architect. 
In all cases the visible arrises must be undamaged. 

6. The hard, wire-cut gault bricks are to be (obtained from 

. . ) or (to be equal to the manufacture of.) 

similar in all respects to the samples approved by the architect 








GENERAL SPECIFICATION CLAUSES 163 

7. The cutters or rubbers are to be obtained from. 

or other approved manufacturer, equal in quality, free from all 
lumps and flaws, and similar in all respects to those approved by 
the architect. 

8 . The salt-glazed facing bricks must be slip-glazed, and are to 

be obtained from.or other approved manufacturer 

They must be fairly uniform in tint and equal in all respects to 
samples approved by the architect. 

9. The salt-glazed bricks are to be obtained from. 

or other approved manufacturer, fairly uniform in tint, and 
equal in all respects to samples approved by the architect. 

10. Reveals, arches, projecting piers, etc., in salt-glazed work 
are to have bull-nosed angles. Any squints, etc., to be in salt- 
glazed quoins to required angle. 

11. The enamel-glazed bricks are to be obtained from 

.or other approved manufacturer. Samples of the 

required color or colors must be deposited with and approved 
by the architect before any of this work is executed. Provide 
enamel-glazed bull-nosed angle bricks for reveals and arches to 
windows and door, projecting doors, etc. Provide all enamel- 
glazed quoins to required angles for squints, etc. 

12 . The firebricks are to be obtained from. ..or other 

approved maker (raw and unburnt) or (thoroughly burnt and 
vitrified), and equal in all respects to the samples approved by 
the architect. 

13. The smoke flue pipes (with air flues combined) are to be 
of the best fireclay, and of approved stock pattern, to be obtained 

from., and equal to the samples approved by the 

architect. 

14. The moulded strings, stops, cornices, angles, sills, jambs, 
plinths, panels, and keys, etc., shown on details, are to be 
obtained from the same manufacturer supplying the facing 
bricks, and of similar make, equal in all respects to the samples 
approved by the architect. 

15. The coping bricks are to be (as per detail drawing) or (of 

approved stock pattern), from.or other approved 

maker.inch by.inch, straight, and even col¬ 

ored, and all arrises and angles must be perfect. 

16. The bonding bricks for hollow walls are to be obtained 

from., of improved bent pattern, equal to samples 

approved by the architect, and of the following size: Lower 












i66 


BRICKLAYERS’ GUIDE 


flange,.inch; middle flange,.inch; upper flange, 


inch. 

17. The.bricks for (the 4§-inch groined arch work) 

are to be made by.or other approved maker, each 


brick cut to the proper size and radius as shown on the detailed 
drawing, and marked before it leaves the works with a number 
corresponding to that on the drawing showing its proper position 
in the arch. 

SAND, ETC. 

18. To be clean, sharp, pit or fresh-water sand, coarse grained, 
and Of approved quality. To be entirely free from loam, clay, 
dust, or organic matter. If directed it must be washed, when 
used with cement. 

19. If the lime mortar is mixed in a mortar mill, the architect, 
at his discretion, may allow the contractor to substitute a certain 
proportion of clean, hard brick, hard burnt ballast, or other 
approved material in lieu of sand. Such permission shall be 
given in writing, and shall clearly state the exact proportion of 
the substitute material which the contractor will be allowed 
to use. 

WATER 

20. The whole of the water required for the works must be 
perfectly fresh and clean, and free from any chemical or organic 
taint. 

LIME MORTAR 

21. The limes for mortar shall be the best of their respective 
kinds, obtained from (manufacturers approved by the architect) 
(the firms hereinafter specified), and shall be fresh burnt (and 
ground) when brought on the works. 

(Add the following if firms are not specified:) 

The contractor shall supply the architect, at the latter’s re¬ 
quest, with the names of the firms from whom the lime has been 
obtained. 

(A dd the following if firms are specified:) 

The contractor shall satisfy the architect, if required by him 
to do so, that the lime is being obtained from the specified firms. 

(Add the following where ground lime is specified:) 

The contractor must satisfy the architect, by analysis or other¬ 
wise, that the lime is not adulterated or air-slaked. 







GENERAL SPECIFICATION CLAUSES 167 

22. The lime shall be thoroughly slaked at the scene of opera¬ 
tions by the addition of sufficient water. During the process it 
shall be effectually covered over with sand to keep in the heat and 
moisture. All lime must be used within ten days of slaking. 

23. The contractor shall, at his own expense, provide a proper 
mortar mill, worked by steam or other approved power, for the 
due incorporation of the materials, and all expenses in connection 
therewith shall be defrayed by the contractor. 

24. If a mortar mill is not provided for the making of the mor¬ 
tar, the contractor will be required to thoroughly screen the 
materials before mixing to get rid of any dangerous and refractory 
lumps. 

25. A proper stage is to be provided to receive the lime mortar 
when made. The mortar in no case to be deposited on the ground. 

26. The materials for all lime mortars are to be measured in 
the proper stated proportions, in quantities sufficient only for 
each day’s requirements. 

27. Fat lime mortar must not under any circumstances be used 
for the purposes of the specification. 

28. The stone lime mortar for brickwork above ground level 

shall be composed of one part of gray lime (obtained from.) 

and two (three) parts of sand, mixed with a sufficiency of water 
and thoroughly incorporated together (in a mortar mill). (The 
lime and sand shall be mixed together in their dry state before 
being put into the mortar mill.) 

29. The lias lime mortar shall be composed of one part of blue 

lias lime (obtained from.), and one part of sand, 

mixed with a sufficiency of water and thoroughly incorporated 
together (in a mortar mill). (The lias lime mortar for brickwork 
above ground level shall be made in the same manner, but in the 
proportions of one part of lime to two parts of the sand.) (The 
lime and sand in their dry state shall be mixed together on a 
proper stage before being put into the mortar mill.) 

30. The blue mortar shall be composed of three parts of fine 
foundry ashes, two parts of ground stone lime, and two parts 
of sand 


CEMENT MORTAR 

31. A proper stage is to be provided for mixing Portland and 
Roman cement mortar upon, and the water must be added from 
a can with a fine rose. 




i68 


BRICKLAYERS’ GUIDE 


32. No cement mortar that has become partially set shall be 
revived or re-used. 

33. The Portland cement shall be obtained from. 

(an approved maker), and shall be of the best quality composed 
entirely of thoroughly well burnt clinker ground fine enough to 
pass a sieve of 2,500 meshes to the square inch, without leaving 
more than 10 per cent behind. The cement shall not contain 
more than 1 per cent of magnesia and 63 per cent of lime. It 
shall weigh not less than 112 lb. per striked imperial bushel when 
lightly filled into the measure from an inclined trough placed 
12 in. above the top of the measure. 

Test briquettes made of the cement, mixed with 18 per cent 
by weight of water, shall be capable of maintaining—after seven 
days’ immersion in water—a tensile strain of 350 lb. per square 
inch, the immersion to commence within twenty-four hours of the 
briquettes being made. The temperature of the atmosphere and 
water in which the test briquettes are made shall not be less than 
40° Fahr. The tensile strain shall be applied at the rate of about 
400 lb. per minute. 

Samples of the cement when made into a paste with water/ and 
filled into a glass bottle or test-tube must not in setting become 
loose by shrinking from the sides, or crack the vessel. 

34. The cement shall be emptied and spread upon the dry 
wooden floor of a covered shed to a depth not exceeding 2 ft. for 
a period of not less than 14 days (or such other period as may be 
considered necessary) and shall be turned over from time to time 
as may be directed by the architect. 

35. The cement shall be delivered on the works in such quan¬ 
tities as to allow sufficient time for testing before being required 
for use, and the contractor shall be entirely responsible for any 
delay or expense caused by the rejection of cement which does not 
satisfy the special requirements. 

36. The Portland cement mortar shall be composed of one part 
of Portland cement to two parts (one part) of sand, mixed together, 
turned over, and thoroughly incorporated with a sufficiency of 
water. It is to be made in small quantities from time to time as 
required, and must be used within one hour of mixing. 

37. The Roman cement is to be of the very best quality, and 
obtained from an approved manufacturer. The raw stone shall 
be fine grained, and after being thoroughly burnt, shall be ground 
to a fine powder The finished cement must not weigh more than 



GENERAL SPECIFICATION CLAUSES 169 


78 lb. per striked bushel, or more than 70 lb. per trade bushel, 
and must be stored in air-tight drums or casks, and kept in a 
dry place in free air currents. 

38. The Roman cement mortar shall be composed of one part 
of Roman cement and one part of sand, mixed together with a 
sufficiency of water and thoroughly compounded. Owing to the 
quick-setting property of the cement, the mortarjnust be mixed 
by an experienced workman close to the position at which it is 
required and used immediately. When once partially set, it must 
not be revived. 

39. The selenitic cement is to be obtained from the patentees, 
and mixed and used in accordance with the printed instructions 
issued by them. 

40 The fireclay is to be of the best quality, and from the same 
manufacturer supplying the firebricks. 

DAMP COURSES 

41. The damp course is to be formed with stoneware (fireclay) 
perforated vitrified blocks ... .in. by ... .in., and of the several 
widths required for the respective walls. The blocks are to have 
ribbed surfaces and tongue and grooved joints. 

42. The bituminous sheet damp course is to be obtained from 

.and laid (in accordance with their instructions) by 

them (the contractor given due and reasonable notice, as arranged, 
when the walls are ready, so that there may be no delay). 


WORKMANSHIP CLAUSES FOR GENERAL WORK 

PRELIMINARY 

43. All brickwork is to be set out and built of the respective 
dimensions, thicknesses, and heights shown on the drawings. 

44. All bricks are to be well wetted before being laid. The tops 
of the walls where left off are to be well wetted before recom¬ 
mencing them, as often as the architect may deem necessary. 

45. All joints are to be thoroughly flushed up as the work pro¬ 
ceeds. The vertical joints in the heading courses of English bond 
are to receive special attention. 

46. Carry up walls in a uniform manner, no one portion being 
raised more than 3 ft above another at one time. All perpends, 



lyo 


BRICKLAYERS’ GUIDE 


quoins, etc., to be kept strictly true and square, and the whole 
properly bonded together and levelled round at each floor. 

47. No brickwork is to be carried on during frosty weather, 
unless with the written permission of the architect who will give 
special directions as to the manner in which the work is to be per¬ 
formed. All brickwork laid during the day shall (in seasons liable 
to frost) be properly covered up at night with felt, sacking, 
boards, or other approved non-conducting material. Should any 
brickwork, laid on the day previous to a frost, become affected or 
damaged through not being covered or properly protected as pre¬ 
viously specified, or by reason of the exceptional severity of the 
weather, the architect, at his discretion, may require the whole or 
any part of such brickwork to be removed and reinstated by the 
contractor at his own expense. 

BOND 

48. Brickwork generally except facings (all brickwork) to be 
laid in English bond consisting of alternate courses of headers and 
stretchers. Snap headers will not be permitted, and bats only as 
closers. 

49. All facings are to be executed in Flemish bond, consisting 
in each course of headers and stretchers alternately, to break joint 
accurately. 

50. Cut indents in alternate courses of existing brickwork, and 
tooth and bond new brickwork to same in cement mortar. 

51. Lay in walls, at intervals of four courses, a layer of 1§ in. 
stabbed hoop-iron to each 4§ in. of thickness of wall, lapped or 
hooked at all angles. 


JOINTS AND POINTING 

52 The height of four courses of bricks laid in mortar is not to 
exceed by more than one inch the height of the same bricks laid 
dry. 

53. The exterior facings are to be pointed with a neat weather 
joint in cement (blue mortar) cut in top and bottom, a sample of 
which is to be approved. 

54. The interior facings to cellars are to be pointed with a flush 
joint neatly struck with the point of the trowel. 

55. The joints to gauged work are to be pointed with. 

(time putty) (cement mortar). 

56. The enamel and salt-glazed facings to be flush pointed in 



GENERAL SPECIFICATION CLAUSES 171 


Parian cement, tinted to color of the glaze, the white enamel- 
glazed facings to be flush pointed in Keen’s cement. 

57- All internal walls, excepting those otherwise described, to 
be left rough for plaster. 

58. Rake out joints for and point to all flashings in cement and 
also all frames. 


FOOTINGS AND PIERS 

59. Footings to be formed to spread on each side of the walls, 
half the respective thickness of same at base, diminishing in reg¬ 
ular 2\ in. offsets to proper thickness of walls. The courses of 
footings are to be laid of headers where practicable. 

60. All underpinning to be executed with approved hard bricks, 
laid in cement mortar, w T ell grouted at every course, and carefully 
wedged up with slate, provided by the contractor. 

61. Lay over the full thickness of all walls and piers at the lev¬ 
els shown on drawings the.horizontal damp course. 

62. The outside faces of vault walls, dry areas to have approved 
asphalt damp course, | in. thick, laid thereon from the level of 
horizontal damp course to top of walls, and continued over top of 
vaults, and turned up around coal or ventilating plates or pave¬ 
ment lights, as required, to make vaults thoroughly water-tight. 

63. All isolated piers carrying weights, and elsewhere if de¬ 
scribed, to be built in pressed bricks laid in cement and grouted 
at every fourth course. 

64. Build honeycomb (solid) fender walls on proper footings to 
ground floors where shown. 

65. (a) Build up dry area wall as shown on drawings in cement 
mortar, arched over into main wall three inches below ground level. 

(6) Build up dry area wall as shown on drawings in cement 
mortar. Bed and point stone cover (provided by “Mason”), as 
shown, in cement mortar. 

WALLS GENERALLY 

66. Build in, or cut' bed, and pin in, all sills, thresholds, steps, 
landings, corbels, ends of joists, etc., in cement, and point as re¬ 
quired. Build in frames, bedded solid in reveals, where specified 
to be built in. 

67. Brickwork to be well pinned and backed up to all stone¬ 
work and terra-cotta, and cut and fitted to ends of all steel joists, 
girders, lintels, etc. 



172 


BRICKLAYERS’ GUIDE 


68. Build in brickwork where required, fixing blocks (pro\ided 
by “concretor”) for fixing carpenters’ or other work. 

69. Build half-brick walls, small piers between windows and 
elsewhere as directed, in cement mortar. 

70. Build chases and reveals in walls to receive frames, pipes, 
light wiring, etc., as shown on drawings, or required. 

71. Bed all plates, lintels, templates, cover stones, etc., in 
cement as required. 

72. Neatly cut and fit all facings to stone or terra-cotta dress¬ 
ings, arches, etc., and execute all rough and fair cutting as required. 

73. Leave horizontal chases in walls to receive concrete floors 
or build sailing courses as shown to support same. 

74. Turn rough segmental relieving arches in cement over all 
lintels where practicable. 

75. Oversail where possible to support concrete floors and pro¬ 
jections and to receive plates. 

76. Level up on top of all riveted girders with plain tiles and 
cement. 

77. Build in.air bricks (provided by “terra¬ 

cotta and Faience worker”) (“founder”), where shown on draw¬ 
ings, and form cranked air-ducts to them in the wall, rendered in 
cement and sand. 

78. The panels intended for carving are to be executed in rubber 
brick, as shown on drawings, set in shellac. 

79. All niches, panels, and other enrichments to be executed in 
.as shown on drawings. 

FIREPLACES, CHIMNEYS, ETC. 

80. Build in over each fireplace opening a wrought iron bar, 
provided by “smith,” turn rough brick segmental arch over same 
in two rings, and properly contract the opening, and form throats 
to flues as detailed. 

81. Build all smoke and ventilation flues of full bore shown, 
graduate all bends and parget flues as the work proceeds, and 
carefully core same, leaving openings in -face of chimney-breasts 
where required for coring, and afterwards pin up same and make 
good. 

82. Line all flues shown circular on plan with.in. un¬ 

glazed terra-cotta flue pipes, and provide all requisite bends, pur¬ 
pose made or otherwise. 

83. Properly bond the withes and other brickwork of all flues. 





GENERAL SPECIFICATION CLAUSES 173 


84. Build all chimney stacks above roof line in cement mortar 
with selected pots set in same, and well flaunched up and weath¬ 
ered in cement, to detailed drawing, joints left open for pointing 
as other brickwork. 

85. Rough render all chimney-backs, and also brickwork to 
flues where near woodwork, in cement. 

86 . Carefully set all stoves, provided by “founder,” with brick 
in mortar backing, fix iron and wood mantels securely with iron 
cramps pinned in cement; set kitchener in accordance with in¬ 
structions with firebrick flues, and provide all firelumps, fireclay, 
etc., required. 

87. Carefully set, where shown on drawings, all flue plates and 
soot doors and frames, provided by “founder.” 

88. Set in brickwork, as described, with firebrick linings in fire¬ 
clay to flues, furnace pan, including all ironwork, dampers, soot 
doors, etc., provided by “founder”; the top and front to be ren¬ 
dered with Portland cement and sand, in equal proportions, f in. 
thick. 

89. Turn half-brick trimmer arches in cement 18 in. wide and 
12 in. longer at each end than the width of the openings to all 
fireplaces where there is no support underneath. 

90. Bed and point hearthstones in cement mortar. 

FACINGS 

91. Face the whole of the_.excepting where otherwise 

specified, with best selected stock bricks, uniform in color. 

92. All arches occurring in stock brick facings to be segmental 
arches in second quality malms, axed and set in cement. 

93 . Face the elevations tinted.on drawings with 

. >8 first quality. ..facing bricks, carefully 

executed in accordance with details of elevations. Build all 
moulded strings, cornices, angles, etc., in similar red bricks, with 
moulded stops as shown on details. 

94. Turn over all basement openings in.elevations, 

plain segmental arches in.rings in cement. Turn over 

all other openings where shown in brick on.elevations, 

gauged arches in red rubbers, accurately and closely jointed. 
That elliptic arches over. . . ..-floor openings on.eleva¬ 

tions to have voussoirs of similar gauged rubbers, alternating 
with terra-cotta voussoirs, provided by “terra-cotta and Faience 
worker,” and moulded to details, 










174 


BRICKLAYERS’ GUIDE 


95. Face the following portions of back elevations: the light 

area to.and also the walls of lavatories in vaults, 

with.quality.bricks in fine mortar. 

96. Reveals and arches to windows and doorways occurring in 
glazed work are to have bull-nosed angles, also all projecting piers 
in lavatories to have ditto. Any squints, etc., to be in white glazed 
quoins to required angle. 

97. Turn segmental arches in glazed half brick rings in cement 
over openings as shown on elevations. 

SUNDRIES 

98. Build in. (glazed brick) piers (in scullery), where shown 
on drawings, to support stoneware (stone) sink, and properly bed 
and point same in cement mortar. 

99. Cope parapets where shown to have brick coping, with two 
courses of plain tiles bedded in cement to project 1 £ in. from faces 

of wall, or. patent drip tiles, and brick on edge 

coping the thickness of wall bedded and pointed in cement mortar 
and ramped as required. 

100 . Cope parapets and other walls where shown with purpose 

made coping bricks the thickness of the wall, pattern No. 

..’s list, bedded and pointed in cement mortar.. 

101. Bed and point stone copings, provided by “mason,” in 
cement mortar with the joints joggled. 

102 . Cut and pin in ventilating flues where shown approved 
ventilators, provided by “ventilating engineer.” 

103. The contractor shall, before pointing, clean down all brick 
facings, and make good all putlog and other holes throughout the 
work as it proceeds, and point the same. 

104. Cut away, etc., as required for other trades, and make 
good after same. 

For Limewhiting, see “Painter’s Specifications.” 

HOLLOW WALLS 

105. Build up the hollow walls as shown on drawings in two 

thicknesses, the outer thickness to be 4£ in., the inner.in., 

with a 2 |-in. cavity between, the thickness of the entire wall being 

.in. Bond the two thicknesses together with. 

wall ties placed at a distance apart of 3 ft. horizontally an ^ 1 12 in. 
vertically. The cavity is to be kept clear of all rubbish or 











GENERAL SPECIFICATION CLAUSES 175 


mortar droppings by movable boards or other means. Leave 
openings at the base and clean out the cavity at completion, the 
openings afterwards to be bricked up uniform with surrounding 
work. The wall ties to be carefully laid and in no case to fall 
towards the inner thickness of the wall. Build into inner face 
of exterior thickness overall frames a piece of sheet lead, provided 
by “plumber,” projecting 2 in. beyond each side of lintel and 
turned up 1 £ in. 

DAMP-PROOF WALLING 

106. Build up the walls in two thicknesses, the outer thickness 

being 4J in., the inner thickness.in., with a £-in. cavity 

between, the total thickness of the wail being.in. The 

bricklayer is to leave the cavity face joints free of mortar for a 
depth of l in., the cavity being kept clear of mortar droppings 
with a movable plain board. At a height of every four courses 
fill up the cavity with.building composition, pre¬ 

pared and used according to instructions. 

RETAINING WALLS 

107. The retaining wall to be carried up according to the 

detail drawing, to be built of.bricks laid in cement 

mortar grouted at every fourth course, to have the exterior face 
battered, the inner face finished with (diminishing offsets; all as 
shown. 

108. Build in where shown 3 in. land drain pipes to run through 
the entire thickness of the wall, cut bricks tp fit, and make good 
around same in cement mortar. 

FACTORY CHIMNEY SHAFT 

For specification of Iron Cap, see “Founder.” For Lightning 
Conductor, see “Electrician.” For Painting Iron Cap, see 
“Painter and Decorator’s Specifications.” 

109. The whole of the brickwork throughout, including foot¬ 
ings, walls, arches, string courses, cornices, etc., is to be built 
and carried up in accordance with the drawings, and is to be of 
the various thicknesses, heights, etc., or other dimensions as 

shown thereon, finishing at the top length of.ft., which is 

to be.ft.in. in thickness and is to be set in cement 

mortar. 








176 


BRICKLAYERS’ GUIDE 


110. All brickwork, except where otherwise specified, is to be 
built in lime mortar and in old English bond. 

All the walls are to be carried up uniformly all round, and no 
part is to be left more than 3 ft. lower than any other. Each 
course is to be carried up to a uniform level throughout, and the 
whole of the work is to be built true, and the perpends strictly kept. 

111. Two arched openings are to be formed (.ft. by 

.ft.) in the base of the shaft, as shown, for the connection 

of the main flues thereto. The semicircular arches over open¬ 
ings to be turned in three 4| rings of brickwork carefully bonded 
in mortar and lined with firebrick. 

112. Form sunk panels in each side of the square pedestal base 
of the dimensions, and after the manner shown upon the drawings. 

113. The brickwork is to be built with neat close joints not 
exceeding J in. in thickness, and no four courses of bricks to rise 
more than 1 in. in addition to the height of the bricks laid dry. 

The cross joints are to be put in solid throughout the whole 
width of the bricks and the wall joints flushed up solid, and 
grouted with every course. 

The bricks for facing must be properly bonded in at each course 
with the brickwork as the work proceeds. 

114. The contractor shall do all cutting required for forming 
openings, splays, miters, chases, circular work, indents, recesses 
and skewbacks, and shall make good all putlog and other holes 
throughout the work as it proceeds, and point the same. 

115. The whole of the exterior brick facing is to be pointed 
with a neat flat joint, and is to be jointed. 

The interior faces of walls are to be jointed with a neat flat 
and flush joint. 

116. The.'..ft. by.ft. main flue entrance in the 

base of the shaft which is not required for immediate use is to be 
built up as shown on plan, with 14-in. brickwork, consisting 
externally of 9-in. ordinary bricks and \\ in. internal facing of 
firebrick properly bonded thereto. 

117. Build in a 3-in. cast-iron pipe (water main strength), with 
a screw hexagonal cap and spanner through the brickwork in the 
position shown upon the plan, for the purpose of inserting testing 
apparatus, etc. 


118- The.brick cornices to be constructed in the top¬ 
most.ft length of the shaft, are to be of depths and 


projections shown upon the plans. They are to be thoroughly 








GENERAL SPECIFICATION CLAUSES 177 


well bonded together and set in cement, and if considered neces¬ 
sary by the architect are to be further secured with metal cramps 
run in with lead. 

119. In the topmost length of the shaft, and between the two 
projecting blue brick cornices above mentioned, five projecting 
ribs are to be formed of facing bricks on each side of the octagon, 
as shown on the drawings. These ribs are to be spaced 41 in. 
apart in the clear, are to be in. in width on the face, to project 

3 in. from the face of the shaft, and are to extend.ft. in 

length. They are to be properly corbelled out at the bottom, 
and finished at the top with splayed blue bricks. All to be set 
in Portland cement mortar. 

120. The shaft is to be internally lined with firebrick from the 
level of the floor of the main flue at its entrance at the base of the 

shaft to a height of.ft. above floor of main flue. The 

firebrick lining is to be built circular, is to be 4§ in. in thickness 

and is to have an internal diameter of.ft. throughout its 

height. An air space of 2| in. in width is to be maintained at the 
back of the firebrick lining, between it and the ordinary brick¬ 
work. At the upper extremity of the firebrick lining this air space 
is to be completely oversailed with firebricks bonded into the 
brickwork, and projecting as shown on the plan. The contractor 
must be very careful to keep the air space perfectly clear of mor¬ 
tar or rubbish of any kind. To permit of an air current between 
the lining and the brickwork, a sliding grid ventilator is to be 
built in each face of the base of the shaft, near the ground level 
and a corresponding grid without slides is to be built in each 
case of the shaft just under the out-sailing course at the top 
of the lining. All firebrick linings are to be built of the best 

.purpose-made radius firebricks, well wetted 

before use, solidly and truly set with the closest possible 
joints, in pure fireclay cement. The firebrick lining is to be 
bonded or stayed at intervals as may be necessary for securing 
same by firebrick bonders into the ordinary brickwork. 

BRICKWORK DURING FROST 

122. The bricks to be used for brickwork during frost shall be 
kept under cover free from moisture or frost. They are to be 
taken out only in small quantities as required for use, and are 
not to be wetted previous to being laid. 

123. The water, sand and lime for the mortar must similarly 






178 


BRICKLAYERS’ GUIDE 


be kept under cover, free from frost. The lime is to be ground 
unslaked lime, mixed with the sand in the proportion of one part 
of lime to two parts of sand. Where the temperature is under 26° 
Fahr. the proportions shall be one part of lime to one part of sand. 
The mortar shall be mixed in ashes having a temperature of not 
less than 34° Fahr. in small quantities as required and used imme¬ 
diately. 

124. The brickwork is to be executed as rapidly as possible 
consistent with good workmanship, and the courses shall be imme¬ 
diately covered with sacking as the work proceeds. 

125. If the temperature shows the presence of more than 12° 
of frost, i. e., a temperature less than 20° Fahr., the work shall be 
immediately stopped. 

Note. —The following are for brickwork for other trades. 

FOR “dRAINLAYER” (HOUSE DRAINAGE) 

126. Construct the manholes to the sizes and depths shown 
on the drawings, all depths being calculated from the inverts 
of the main channels in the manholes. The manholes are not 
to be built until the pipes entering them, have been properly 
laid and jointed. 

127. The walls to be built of the full dimensions shown on the 
drawings in selected hard stocks laid in cement mortar in English 

bond. (The interior face joints for a distance of.ft. above 

the benches are to be left rough as a key for the rendering.) All 
(other) joints to be thoroughly flushed up with cement mortar, 
and are to be neatly struck with the point of the trowel. Point 
in cement the (exposed) brickwork to interior faces of manholes. 

Note. —Some architects prefer to have manholes in stock 
bricks rendered on the interior faces in cement and sand. If ren¬ 
dering is not desired leave out the words in brackets. 

128. The walls to be built of the full thicknesses shown on the 
drawing, of good hard stocks, with interior facings of (enamel 
glazed) (salt glazed) bricks in cement mortar in English bond, the 
joints to be well flushed up, grouted at every fourth course, the 
brickwork to interior faces being pointed in pure cement and 
neatly struck with the point of the trowel. 

129. To be built as other manholes, but in addition to have a 

small brick chamber constructed at the side, 14 in by 14 in. by 
27 in. in the clear,.as shown on drawings An aperture to be 
formed in the division walls, and to have a.mica valve 




GENERAL SPECIFICATION CLAUSES 179 

built in as shown on drawings as near the top of the manhole as 
practicable. 

130. A chamber is to be formed at one end of.man¬ 

holes by turning an arch in two 4£- in. rings from side to side as 
shown on drawings. The height of such chamber from the invert 
of the main channel to be 6 ft. 

131. A chamber is to be formed at one end of the.man¬ 

hole by partially roofing over with a good stone cover or landing 
as shown on drawings. The height of such chamber from the 
invert of the main channel to the underside of the stone to be not 
less than 6 ft. or more than 6 ft. 2 in. as the courses of brickwork 
allow. 

132. Build up the walls to the heights, lengths, and thicknesses 
shown on detail drawing (1 stock 2. blue) bricks laid in cement 
mortar (1. the interior face joints left rough for rendering) 
(2. grouted in at every course and the'joints being neatly struck 
with the point of the trowel). Form an aperature in division 
wall 9 in. by 12 in. as shown. Build in stone cover to aperture, 
stone templates under R. S. joists, hooks for grating chains, etc., 
as shown on detail. Secure grating channel to walls of filter 
chamber with holdfasts driven 6 in. into the brickwork. (1. The 
whole of the interior faces of tank and filter to be rendered and 
smoothly troweled in cement and sand f-in. thick.) 

133. Build in the ends of all pipes at the heights and levels 
shown on the drawings, or as directed by the architect during the 
construction of the manholes, rain water tank, and filter etc. 
Build in step-irons at a height of every four courses of brickwork 
where shown on plan. 

134. All drainpipes passing through manhole, R. W. tanks, 
filter, or other walls or foundations are to have arched openings 
formed for them so that they can be withdrawn without cutting 
and to prevent fractures from settlements. 

135. The entrances to manholes, R. W. tanks, filter, etc., are to 
be corbeled over to the necessary openings for covers, as shown 
on drawings. 

136. The walls to be 9 in. in thickness, built of stock bricks, 
laid in cement mortar or English bond. The interior face joints 
of brickwork to be left rough for rendering. The walls to be 
carried up perpendicularly for flat stone cover. 

137. Bed and point all stone covers and landings to manholes 
in cement mortar bed and point stone covers to cleaning and 




i8o 


BRICKLAYERS* GUIDE 


inspection eyes, inspection chambers and all movable covers in 
lias lime mortar. 

138. Bed and point all iron cover frames to manholes, R. W. 
tanks, inspection chambers, lamp holes, etc., where shown on 
drawings, in cement mortar. 

DRAINAGE 

139. At the points shown build inspection chambers (or catch- 

pits),.ft. by.ft. internal diameter, in solid 9-in. 

stock brick, in cement mortar according to detail, the inlet and 
outlet pipes being built in as directed. 

140. Build up face wall at outfall in good hard stocks, 9 in. in 
thickness, laid in cement mortar. Build in over the drain mouth 
close iron grating provided by “smith.” The last pipe to be 
built in to slope slightly downwards and a little projecting in 
order that the effluent may discharge clear of the face of the wall, 
all according to detail. 

FOR “MECHANICAL ENGINEER” 

141. Build the engine bed in stock brickwork, and bed on 
stone cover supplied by “mason.” 

142. Build for and set the boilers.according 

to detail drawing in stock and firebrick. 

143. The boiler to be set on fireclay seating blocks, 12 in. long, 
separated from boiler by wrought iron strips. 

144. Line the flues with 4§-in. firebrick and finish against side 
of boiler with 9 in. by 9 in. quadrant fireblocks. 

145. The seating at front end of boiler to be faced out with 
white enamel glazed brick in fine mortar, and neatly cut to same. 

146. Line the blow-off pit with white glazed brick as above, 
with firebrick bottom. Build in iron drain pipe and bed stone 
cover supplied by “mason.” 

147. Form main flue under boilers.ft. wide, carry 

through wall.ft. by.ft. The arched flue to chim¬ 
ney to be.ft. wide and.to crown in 9. in. stock 

brickwork with 4^-in. firebrick lining. 

148. Build manhole to ditto.ft. by.ft. in 9-in. 

brickwork. Wall up the opening to flue with straight jointed 
bricks, so as to be removed when required and form sump in ditto. 

149. Cover in boiler side and flues with stone flags supplied 
by “mason.” 












STONEMASONS’ GUIDE 


PART II 

MASONS’ WORK 

INTRODUCTION 

A mason, properly speaking, means a builder, which 
is evident from the connection between the French 
words ma?on, a mason; maison, a house, and maison- 
ner, to build houses; but in America it is customary to 
look upon a mason and a stone mason as one and the 
same, a builder in bricks being always called a brick¬ 
layer. In Ireland the term masonry is specially 
applied to stone-walling, as distinguished from the cut 
stonework used in dressings and other work of a 
superior description. 

In this country masonry is the art of building in 
stone in a similar manner to that of brick, with the 
exception that brickwork is carried out with uniform 
sized blocks, thus admitting of a number of definite 
systems ol laying the bricks; whereas in stone, owing 
to the expense in working the material, the face stones 
only are squared, and the interior or hearting is filled 
up with smaller stones roughly fitted with a hammer. 
The stones are in the great majority of cases of vary¬ 
ing dimensions, thereby making it a matter of great 
skill to obtain a proper bond in the work; and owing 
to the irregular shape of the material the walls have 
to be made considerably thicker than walls of the same 
height in brick, with the exception where the walls 
are built of coursed stones properly squared, in which 

181 


182 


STONEMASONS’ GUIDE 


case the thickness may be even less than that of brick 
walls. 

The great dimensions in which stone may be 
obtained, lends itself to a much greater degree than 
bricks for buildings of architectural pretensions, ren¬ 
dering it possible to have cornices and corbelled work 
of great projection, which is impossible in brickwork. 


TECHNICAL TERMS 

The following is a list, and also an explanation, of 
some terms used in stonework: 

Bond, Lap, and Course. —These terms have the same 
meaning as given under brickwork. 

Through Stones. —Stones which extend through the 
entire thickness of walls to tie or bond them. These 
are objectionable, as damp is more likely to show on 
the interior of walls where the continuity of the mate¬ 
rial is uninterrupted. 

Headers. —The name applied to stones, the lengths 
of which are 2 /i to ^ thickness of the wall, laid trans¬ 
versely. 

Bonders. —These may be either “throughs” or 
“headers.” 

Grout.—This is a thin mortar, which is poured over 
the stones when brought up to a level surface, to fill 
up any interstices between the stones In the hearting 
of walls or other positions as necessity requires. 

Spalls or Shivers. —These are broken chips of stone, 
worked off in the dressing. 

Weathering.—The top face of a stone worked to a 
plane surface inclined to the horizontal for the pur¬ 
pose of throwing off the water is said to be weathered, 
as in sills, cornices, etc. 


TECHNICAL TERMS 


183 


Footings.—The object of footings is the same as in 
brick walls. Stone footings should be large, rectan¬ 
gular, through stone blocks. Square stones in plan 
are not so good as oblong. All stones in the same 
course must be of the same height, but all courses 
need not necessarily be of the same depth. The 
breadth of set-offs need not exceed 3 or 4 in. 

If the expense of stone is an objection, footings 
may be made of bricks or beds of concrete of suffi¬ 
cient depth. See chapters on Foundation and on 
Brickwork. 

Bed Surface.—The bed surface must be worked in one 
plane surface. Masons, to form thin joints, often make 
the beds hollow. This is bad, as it is liable to spall; 
all the pressure will be thrown on the outer part, which 
is liable to spall the edge of the stone. 

Galleting.—The term given when small pebbles are 
pressed into the face joints of rubble walls to preserve 
the mortar and to give a pleasing effect. 

Dressings.—Stones are said to be dressed when their 
faces are brought to a fair surface; but cut or prepared 
stones used as finishings to quoins, window and door 
openings, are described as dressings. 

Quoins.—In rubble and inferior stone walls, quoins 
are built of good blocks of ashlar stone to give 
strength to the wall. These are someti.mes worked to 
give a pleasing effect, and where hammer dressed and 
chamfered are said to be rusticated. They are, at 
times, merely built with a rough or quarry face, only 
having the four face edges of each stone lying in one 
plane. 

"Window and Door Jambs.—For purposes of strength 
these should be of cut stone, attention being given 
that each course is securely bonded. For that reason 


184 


STONEMASONS’ GUIDE 


it would not be advisable to build them of rubble. 

Stoncheons. —The stones forming the inside angle of 
the jamb of a door or window opening. These are 
often cast in concrete to effect a saving in labor. 

Sills. —These are the lower horizontal members of 
openings; those in stone are usually of one length, 
being pinned in cement to both sides of the opening. 
They should be fixed after the carcass of a building 
has been finished, and any settlement that was likely 
to occur through a number of wet mortar joints has 
taken place. They may be plain and square, as for 
door sills, or sunk, weathered, moulded with drip and 
with properly formed stools, and grooved for metal 
water bar, or moulded, grooved and weathered. 

Corbel.—A stone projecting from a wall to support a 
projecting feature. 

Skew Corbel. —Is a projecting stone at the lowest 
part of the triangular portion of the gable end of a 
wall supporting the starting piece of coping, and 
resisting the sliding tendency of the latter. The skew 
corbels are often tied into the wall by long iron 
cramps. 

Kneeler or Skewput. —This is a long stone, tailing 
well into the gable wall, and resists the sliding tend¬ 
ency of the coping. 

Saddle or Apex Stone. —The highest stone of a gable 
end, cut to form the termination of two adjacent 
inclined surfaces. 

Lacing Course. —Owing to the absence of bond in 
some walls, courses of bricks, three deep, are inserted 
at intervals, to give strength to the wall and bring it 
to a level surface. Sometimes the name is applied to 
a horizontal band of stone placed in rubble or rough 
walls to form a longitudinal tie. 


TECHNICAL TERMS 


185 


String Courses. —Horizontal bands of stone sometimes 
moulded and projecting, often carried below windows 
to accentuate the horizontal divisions of a building. 

Plinth.—A horizontal projecting course or courses 
built at the base of a wall. These are to protect the 
wall, and are often built in hard hammer-dressed 
stones. 

Cornices. —The moulded course of masonry crowning 
buildings, generally having a large projection to 
throw off the rain. 

Saddled or Water Joint. —To protect the joints of 
cornices and other exposed horizontal surfaces of 
masonry, the sinking is sometimes stopped before the 
joint and weathered off. Any water passing down the 
weathered surface is guided away from the joint. 
The expense of this joint often prohibits its use. 

Blocking Course. —A course of stones erected to make 
a termination to the cornice, the object being to gain 
extra weight to tail down the cornice, and to form a 
parapet. 

Coping. —The highest and covering course of masonry, 
forming a waterproof top, to preserve the interior of 
wall from wet, which in frosty weather might burst 
the wall. Fig. 52, B. shows a coping flat on the top sur¬ 
face, which should be used only for inclined surfaces, 
as on a gable, or in sheltered positions. Saddle-back 
is the name applied when the upper surface is weath¬ 
ered both ways; and segmental, when the section of 
copings shows the upper surface to be a part of a circle. 

Rebated Joints. —These joints are used for stone 
roofs and copings to obtain weather-tight joints. 
There are two kinds: 1, when both stones are rebated; 
2, when the upper stone only is rebated. In the first 
case the stones are of the same thickness throughout, 


STONEMASONS’ GUIDE 


186 

their upper surface being level when the joint is made. 
In the second case the stones are thicker at the bottom 
edges than at the top, the bottom edge having a rebate 
taken out equal to the thickness of the upper edge of 
the stone below it, over which it fits. The part that 
laps over should not be less than % in. thick. The 
upper surfaces or beds of the stones should be level. 

Throatings. —Grooves on the under surfaces of cop¬ 
ings, sills, string courses, etc., acting as drips for any 
water that would otherwise trickle down and disfigure 
the walls. 

Templates. —Slabs of stone placed under the end of a 
beam or girder to distribute the weight over a greater 
area. 

Gable Details. —The tops of stone walls are protected 
by coping, and these, where placed on steep gables, 
need support at their lower ends and at intervals; this 
may be done by constructing a shoulder at the foot, or 
by the use of skew corbels. The intermediate sup¬ 
ports are obtained by kneelers, which consist of stones 
having a part worked as a coping, the remainder tail¬ 
ing well into the wall. 

Corbie Step Gables. “A common method of finishing 
gables is by constructing a number of steps formed of 
some hard stone squared, the top surfaces being 
slightly weathered and known as corbie or crow-step 
gabling. 

Gablets. —Many skew corbels are constructed with a 
small gablet, which gives extra weight to the skew 
corbel, thus rendering it more efficient for resisting 
the outward thrust of the coping stones. The apex 
stones are often treated in a similar manner. 

Corbel-table. —A system of corbeling supporting a 
parapet, often forming an architectural feature. 


TECHNICAL TERMS 18/ 

Pinial. —The aspiring ornament of an apex stone 
often richly foliated. 

Parapet. —The fence wall in front of the gutter at the 
eaves of a roof. The castellated parapet is formed'by 
a number of embrasures similar to the parapets used 
in ancient military buildings, much used in the later 
Gothic work as an ornamental feature. 

Diaper Work. —Is the name given to bands, surfaces 
and panels in the stone work formed by square stones 
and similar squares, filled in with brick or flint work, 
giving a checkered appearance. The term is also 
applied to any ornament arranged in squares upon the 
surface of ashlar masonry. 

Tympanum. —The masonry filling in between the 
relieving arch and the head of a door or window. 
Advantage is often taken of this to form a ground for 
carved ornament. 

Gargoyle. —Is a stone water-spout, employed in build¬ 
ings of Gothic character to carry off the rain from the 
gutters. These project sufficiently far to throw the 
water clear of the building. At present down pipes 
are employed, but the gargoyle is often retained as an 
overflow in lieu of a warning pipe. 

Tailing Irons. —These are formed of H, L, or T irons 
for holding down the ends of corbels in oriel windows. 

Lintels.—Wide spans requiring to be bridged by 
stone lintels (as is the case in the trabeated styles of 
architecture) are often of a greater dimension than can 
be conveniently obtained in one stone, in which case 
the lintel is built up in one of two ways: 

(1) By an arched construction. The sloping joints 
in this method are considered objectionable by some, 
altering as it does the principle of the construction 
from the beam to the arch, the number of small pieces 


i88 


STONEMASONS’ GUIDE 


detracting from the general effect. Vertical joints are 
preferred to inclined. The arched principle, with 
vertical jointed voussoirs, may be carried out by form¬ 
ing the joint vertically on and about 4 in. below the 
face and the remainder to the back, or, if seen on both 
sides, in the center of the lintel. The stone cut thus 
form voussoirs of an inch. 

(2) The method now most usually adopted is to build 
the lintel up of a number of pieces with vertical joints 
and in two thicknesses, the front and back portion 
being made to envelop the flanges of a steel girder, 
which bridges the whole span and takes its bearing on 
the columns. The back and front pieces are connected 
on the soffit, and the upper surface by small copper 
cramps, the latter being bedded in cement mixed with 
dust from the Stones to be united. The hole soffit is 
finally rubbed over with a piece of stone similar to the 
lintels, to render the joint as nearly as possible invis¬ 
ible. Care must be taken to protect the iron girder 
from the danger of oxidation by applying one of the 
preservative processes employed for iron and steel. 

The stone entablatures built over shop fronts are 
formed in this way, but have the stone on one side 
only of the girder, being connected to the same with 
cramps. 

The masonry above stone lintels should be disposed 
to throw, as much as possible, the weight of the super¬ 
imposed walling on to the supports, and not unneces¬ 
sarily stress the lintel. 

Labors. —The following are the chief labors adopted 
in preparing stone work: 

Half-Sawing.— The surface left by the saw; half 
the cost of the sawing being charged to each part of 
the separated stone. 


TECHNICAL TERMS 


189 

Self-faced. —The term applied to the quarry face, or 
the surface formed when the stone is detached from 
the mass in the quarry; also the surfaces formed when 
a stone is split in two. 

Scabbling or Scappling. —That is, taking off the 
irregular angles of stone; is usually done at the quarry, 
and is then said to be quarry pitched, hammer faced 
or hammer blocked; when used with such faces the 
stone is called rock or rustic work. 

Hammer Dressing. —Roughest description of work 
after scabbling. 

Chisel Drafted Margin. —To insure good fitting joints 
in hammer faced stones, a true surface about an inch 
wide is cut with a chisel, forming a margin on the face 
of stone. 

Plain Work. —This is divided, for purposes of valua¬ 
tion, into half plain and plain work. The former term 
is used when the surface of the stone has been brought 
to an approximately true surface, either by the saw or 
with the chisel. Plain work is the term adopted for 
surfaces that have been taken accurately out of wind¬ 
ing with the chisel. Half plain is usually placed upon 
the bed and side joints of stones in ashlar work and 
plain work on the face. 

Rubbed Work. —This labor consists in rubbing the 
surfaces of stones until perfectly regular, and as 
smooth as possible. The work is accomplished by 
rubbing a piece of stone with a second piece. During 
the first stages of the process, water and sand are 
added, gradually reducing the quantity of sand up to 
the finish. Large quantities of stones are rubbed by 
means of large revolving iron discs, on which the 
stones are placed, and kept from revolving with the 
disc by means of stationary timbers fixed a few inches 


STONEMASONS’ GUIDE 


190 

above and across the table. Water and sand are added 
to accelerate the process. Only plane surfaces can be 
rubbed in this way. 

Polishing. —Marbles, after the rubbed operation, are 
brought to a still smoother surface by being well 
rubbed with flannel and a paste of beeswax and tur¬ 
pentine or putty. The polishing of granite has been 
described elsewhere. 

Boasted or Droved Work. —This consists in making a 
number of parallel chisel marks across the surface of 
the stone by means of a chisel termed a boaster, 
which has an edge about 2 y 2 in. in width. In this 
labor, the chisel marks are not kept in continuous 
rows across the whole width of the stone. 

Tooled Work.— This labor is a superior form of the 
above, care being taken to keep the chisel marks in 
continuous lines across the width of the stone. The 
object of this and the preceding is to increase the 
effect of large plane surfaces by adding a number of 
shadows and high lights. This labor is sometimes 
known as scabbled work. 

Axed Work. —Axed work and tooled work are similar 
labors. The axe is employed for hard stones, such as 
granite, but the mallet and chisel for soft stones, 
being more expeditious. 

The method of preparing the hard stones after being 
detached from their beds in the quarry is as follows: 
The stones are roughly squared with the spall hammer; 
the beds are then prepared by sinking a chisel draught 
about the four edges of the bed under operation, the 
opposite draughts being out of winding, and the four 
draughts in the same plane surface; the portions pro¬ 
jecting beyond the draught are then taken off with the 
pick. After the pick the surface is wrought with the 


TECHNICAL TERMS 


I 9 I 

axe, the latter being worked vertically downward upon 
the surface, and taken from one side of the stone to 
the other, and making a number of parallel incisions 
or bats; the axe is worked in successive rows across 
the stone, the incisions made being kept continuous 
across the surface. In axed work there are about four 
incisions to the inch. This labor is used for the beds 
of stones for thresholds and curbstones, and in this state 
the pick marks are easily discernible. Fine axed work 
is a finer description of axed work, and is accomplished 
with a much lighter axe having a finer edge. In fine 
axed work there would be eight incisions to the inch. 

Furrowed Work.—This labor, used to accentuate 
quoins, consists in sinking a draught about the four 
sides of the face of a stone, leaving the central portion 
projecting about Y of an inch, in which a number of 
vertical grooves about Y in. wide are sunk. 

Combed or Dragged Work.—This is a labor employed 
to work off all irregularities on the surfaces of soft 
stones. The drag or comb is the implement used. It 
consists of a piece of steel with a number of teeth like 
those of a saw. This is drawn over the surface of the 
stone in all directions, making it approximately 
smooth. 

Vermiculated Work.—This labor is placed chiefly on 
quoin stones to give effect. The process is as follows: 
A margin of about % in. is marked about the edge of 
the stone, and’in the surface enclosed by the margin a 
number of irregularly shaped sinkings are made. 
The latter have a margin of a constant width of aboul 
Ys in.between them. The sinkings are made about %\n. 
in depth. The sunk surface is punched with a pointed 
tool to give it a rough pockmarked appearance. 

Pointed Work.—The bed and side joint of stones are 


192 


STONEMASONS’ GUIDE 


often worked up to an approximately true surface by 
means of a pointed tool or punch. This labor is often 
employed to give a bold appearance to quoin and 
plinth stones, and where so used it usually has a chisel- 
draughted margin about the perimeter. 

Moulded Work.—Mouldings of various profiles arc 
worked upon stones for ornamental effect. Mouldings 
are worked by hand as well as by machine. In the 
former case, the profile of the moulding is marked on 
the two ends of the stone to be treated by means of a 
point drawn about the edge of a zinc mould, cut to the 
shape of the profile. A draught is then sunk in the 
two ends to the shape of the required profile. The 
superfluous stuff is then cut away with the chisel, the 
surface between the two draughts being tested for 
accuracy by means of straight-edges. The machines for 
moulded work somewhat resemble the planing machines 
for metal work. The stone is fixed to a moving table. 
The latter has imparted to it a reciprocating rectilinear 
motion, pressing against a fixed cutter of the shape of 
required profile, or some member of it. The cutter is 
moved near to the stone after each journey, thus 
gradually removing the superfluous stuff till the profile 
is completed. Moulded work is, strictly speaking, the 
name given to profiles formed with a change of curva¬ 
ture, and therefore should not be applied to cylin¬ 
drical sections, such as columns. 

The weathering properties of stoneS moulded by 
hand labor are considered by some far superior to 
those worked by machinery, as in the latter method 
the moulding irons, being driven continuously, 
become heated and partially calcine the surfaces of 
the stones, thus rendering it peculiarly susceptible to 
atmospheric deterioration. 


TECHNICAL TERMS 


193 


Moulded Work Circular. —This term is given to 
mouldings stuck upon circular or curved surfaces in 
plan or elevation. 

Sunk Work.— This term is applied to the labor of 
making any surface below that originally formed, such 
as chamfers, wide grooves, the sloping surfaces of 
sills, etc. If the surface is rough, it is known as half- 
sunk; if smooth, sunk, and any other labor applied 
must be added, such as sunk, rubbed, etc. 

Circular Work. —Labor put upon the surface of any 
convex prismatic body, such as the parallel shaft of 
a column or large moulding, is termed circular work. 

Circular Sunk Work. —Labor put upon the surface of 
any concave prismatic body, such as a large hollow 
moulding, or the soffit of an arch, is termed circular 
sunk work. 

Circular Circular Work. —The labor placed upon 
columns with entases, spherical or domical work. 

Circular Circular Sunk. —The labor worked upon the 
interior concave surfaces of domes, etc. 

Internal Miters. —The name given to the intersections 
of two mouldings making an angle less than 180 
degrees. 

External Miters. —The name given to the intersection 
of two mouldings making an angle greater than 180 
degrees. 

Returned Mitered and Stopped.— The name given to a 
moulding returned in itself, and stopping against an 
intersecting surface. 

Long and Short Work. —This work is often used for 
quoins and dressings in rubble walls, and is especially 
noticeable in old Saxon work. It consists in placing 
alternately a flat slab, which serves as a bonder, and a 
long stone approximately small and square in section. 


194 


STONEMASONS’ GUIDE 


This arrangement in modern work is sometimes 
known as block and start work. 

Stone Walling.—Is divided under the following 
headings: I, Rubble; 2, Block in Course; 3, Ashlar. 
Illustrations of these various kinds of walling will be 
shown later on. 

Rubble walls are those built of thinly bedded stone, 
generally under 9 in. in depth, of irregular shapes as 
in random rubble or squared as in coursed rubble. 

Block in course is composed of squared stones 
usually larger than coursed rubble, and under 12 in. 
in depth. 

Ashlar is the name given to stones, from 12 to 18 
in. deep, dressed with ascabbling hammer, or sawed to 
blocks of given dimensions and carefully worked to 
obtain fine joints. 

The length of a soft stone for resisting pressure 
should not exceed three times its depth; the breadth 
from one-and-a-half to twice its depth; the length in 
harder stones four to five times its depth, and breadth 
three times its depth. 

Random Rubble.—The name given to walling built of 
stones that are not squared, but roughly fitted with a 
waller’s hammer. 

Random Rubble Set Dry.—In the stone districts 
boundary walls are built of rubble set without mortar. 
The top is built of heavy stones, which are usually 
bedded in earth, to prevent slight movement. 

Uncoursed Random Rubble Set in Mortar.—In these 
the stones are used as they come from the quarry, care 
being taken to obtain them as uniform as possible, and 
roughly fitting with the waller’s hammer; one bond 
stone is used in every super yard on face; any open¬ 
ings between stones to be pinned in with spalls. If 


TECHNICAL TERMS 


*95 


good mortar is used, walls built of random rubble 
should be made one-third thicker than the thickness 
necessary for brick walls. 

Random Rubble Built in Courses. —This consists of 
stones forming horizontal beds at intervals of 12 to 18 
in., every stone being bedded in mortar. The object 
of coursing is to insure that there shall be no con¬ 
tinuous vertical joints. To save expense in bedding 
each stone in mortar, masons bed only the stones on 
faces of wall, and at these levels pour a pail of thin 
mortar, called grout, to fill up any cross joints between 
stones, taking care that the hearting stones are prop¬ 
erly interlocked. 

TJncoursed Squared or Snecked Rubble. —Stones roughly 
squared and hammer or axe faced, the vertical depth 
of the stones usually being less than 9 in; to prevent 
continuous long horizontal joints, small stones, termed 
snecks, are placed at intervals adjacent to a large 
stone, the beds of both being level and thereby com¬ 
mencing a horizontal joint at another level. 

Squared Rubble Built in Courses. —Squared rubble is 
brought up to level beds with dressed quoins. The 
coursing is to prevent continuous vertical joints. It is 
sometimes known as irregular coursed rubble, as the 
courses need not all be of a uniform depth. 

Regular Coursed Rubble. —In this kind of work all 
stones in one course are squared to the same height, 
usually varying from 4 in. to 9 in., and are generally 
obtained from thin but regular beds of stone. 

Block in Course is the name applied to stone walling, 
chiefly used by engineers in embankment walls, harbor 
walls, etc., where strength and durability are required. 
The stones are all squared and brought to good fair 
joints, the faces usually being hammer-dressed. Block 


196 


STONEMASONS’ GUIDE 


m course closely resembles coursed rubble, or ashlar, 
according to the quality of the work put upon it. 

Ashlar.—Ashlar is the name applied to stones that 
are carefully worked, and are usually over 12 in. in 
depth. 

As the expense would be too costly to have walls 
built entirely of ashlar, they are constructed to have 
ashlar facing and rubble backing, or ashlar facing and 
brick backing, but, as the backing would have a 
greater number of joints than the ashlar, the backing 
should be built in cement mortar, and brought to a 
level at every bed joint of the ashlar, to insure equality 
of settlement. 

The ashlar facing may be plain, rebated, or cham¬ 
fered, and looks best when laid similar to Flemish 
bond in brickwork. 

JOINTS 

In arranging the joints of masonry the following 
general principles should be observed: 

1. All the bed joints must be arranged at right 
angles to the pressure coming upon them. 

2. Joints should be arranged to prevent any mem¬ 
bers, such as sills, being under a cross-stress. 

3. The joint should be arranged so as to leave no 
acute angles on either of the pieces joined. 

The first condition applies to all kinds of masonry. 
It is necessary to prevent any sliding tendency taking 
place between the stones. 

The second condition applies chiefly to sills in win¬ 
dow openings. These, if in one piece, and built into 
the piers at each side of the opening, are often sub¬ 
jected to a cross-stress, owing to the settlement being 
greater under the piers than beneath the window open- 


JOINTS 


19; 


ings. This danger occurs more frequently in openings 
in the lowest story, and the effect of it is to break the 
sill. In brickwork, this defect is remedied by fixing 
the sill after the whole of the brickwork has been 
erected and the settlement taken place; but in stone¬ 
work, and under conditions where the sill must be fixed 
as the building proceeds, the breaking of the sill may 
be prevented by having a vertical joint in the line of 
the face of the reveal. 

If there are any heavy mullions down which pressure 
may be transmitted, the same precaution must be 
taken with the sill; but if light mullions occur, the 
sill maybe taken continuously through. In such cases 
no joint in the sill should occur under the mullions. 

The third condition applies chiefly to the joints in 
tracery work, and any exposed joints in any other 
work. Stone being a granular material, anything 
approaching an acute angle is liable to weather badly; 
therefore in any tracery work having several bars 
intersecting, a stone must be arranged, to contain the 
intersections and a short length of each bar, and the 
joints should be (a) at right angles to the directions of 
the abutting bars if straight, or (< h ) in the directions of 
a normal to any adjacent curved ban This not only 
prevents any acute angles occurring, as would be the 
case if the joints were made along the line of intersec¬ 
tion of the moulding, but also insures a better finish, 
as the intersection line can be carved more neatly with 
the chisel, and is more lasting than would be the case 
if a mortar joint occurred along the above line. In no 
case, either in tracery, string courses, or other mould¬ 
ings, should a joint occur at any miter line. 

Joints.—These may be classified as follows: 

I. To resist compression, such as the square joint, 


198 


STONEMASONS’ GUIDE 


the surface of which is arranged normal to the pressure. 

2. To resist tension cramps, lead plugs and bolts. 

3. To resist sliding or displacement, joggle, joints, 
tabling dowels and pebbles. 

Joints to Resist Compression. —Joints in stone under a 
compressional stress have plane abutting surfaces 
normal to the stress 

Joints to Resist Tension.— The texture of stone is 
unsuited to form tensional connections. Where there 
is any tensional stress the joints are best held together 
by metal connections. 

Cramps. —Metal cramps are used to bind work 
together, and are particularly adapted for positions in 
which there is a tendency for the stones to come apart, 
such as in copings covering a gable, or in face stones 
of no great depth, or cornices and projecting string 
courses to tie them to the body of the wall. The 
cramps are made from thin pieces of metal of varying 
lengths and sectional area according to the work, 
turned down about 1% in. at each end. The ends are 
made rough and inserted into dovetailed-shaped mor¬ 
tises, and the body in a chase made to receive them in 
the stones to be connected. The cramps are usually 
prepared from either wrought iron, copper, or bronze. 
If wrought iron is used, it is usually subjected to some 
preservative process, such as tarring and sanding or 
galvanizing, to prevent oxidation. Iron is useful on 
account of its great tensile strength. Copper is valued 
for its non-corrosive properties under ordinary condi¬ 
tions, and its tensile strength, which is not much less 
than wrought iron; it is, however, comparatively soft. 
Bronze possesses all the properties of copper necessary 
for cramps, and in addition is much harder, and there¬ 
fore better. 


JOINTS 


199 


The best bedding materials are Portland cement, 
sulphur and sand, asphalt and lead. Care should be 
taken to completely envelop the cramp in the bedding 
materials. Stones are also connected by slate cramps 
set in cement. 

Lead Plugs. —Stones may be connected together by 
means of lead in the following manner: Dovetailed- 
shaped mortices are made to correspond in the side 
joints of two adjacent stones, into which, when placed 
in position, molten lead is poured, and when cool is 
caulked, thus completely filling the mortises and con¬ 
necting the pieces. 

Bolts. —Stone pinnacles, finials, and similar members, 
where built of several stones, are usually connected 
together with iron bolts passing through all of them 
and binding down to some more stable portion of the 
work. Cornices with a great projection are secured by 
long iron bolts, termed anchor bolts, carried well down 
into the body of the work, and at their lower ends 
passing through large iron plates termed anchor plates. 

Rag Bolts. —Are employed to secure ironwork to 
stone. The ends of the bolts are often fixed by having 
the end that is let into the stone jagged, and run with 
lead, or sulphur and sand, the mortise being dovetailed- 
shaped to secure it from any upward pressure. 

Where there is any probability of a great upward 
stress a hole is drilled right through the stone and a 
bolt supplied with a washer passed through in the 
ordinary manner. 

Joints to Resist Sliding. —The following are those 
most used: 

Joggles. —A joggle is a form of joint in which a por¬ 
tion of the side joint of one stone is cut to form a 
projection, and a corresponding sinking is made in 


200 


STONEMASONS’ GUIDE 


the side of the adjacent stone for the reception of the 
projection. It is chiefly used in landings to prevent 
any movement between the stones joined and so retain 
a level surface between them, and also to assist in 
distributing any weight over every stone in the 
landing. 

Tabling Joints. —This is a form of joint that has been 
used to prevent lateral motion in the stones of a wall 
subjected to lateral pressure, such as in a sea-wall. It 
consists of a joggle joint in the bed joints, the projec¬ 
tion in this case being about in. in depth and a 
third of the breadth of the stone in width. This kind 
of joint is rarely used now, owing to the great expense 
in forming it, it being superseded for sea-walls by 
huge blocks of concrete cast on or near the spot, of a 
weight sufficient to resist any pressure likely to be 
brought to bear on them, and usually under other con¬ 
ditions by long slate joggles placed in a space to 
receive them in the bed joint at the junction of side 
joints of two stones and the top bed joint of another. 

Cement Joggles. —These are generally used in the side 
joints of the top courses of masonry to prevent lateral 
movement in them, and consist of a V-shaped sinking 
in the side joint of each adjacent stone in the same 
course. 

Dowels. —Doweling is another method of obtaining 
the same result as joggling or tabling. The dowels 
consist usually of pieces of hard stone or slate about I 
in. square in section, and varying from about 2 in. to 5 
in. in length, slightly tapering from the center towards 
the two ends, being sunk and set in cement in cor¬ 
responding mortises in the adjacent stones. They 
are used in both the side and bed joints. They are 
generally employed in the top courses of masonry 


TOOLS USED IN STONEWORK 


201 


where the weight on or of the individual stones is not 
great. The united mass thus formed from the col¬ 
lected stones renders any movement impossible under 
normal conditions. 

Pebbles. —Small pebbles, owing to the ease with 
which they may be fitted, were formerly employed in 
the jo : nts of stones to prevent sliding. They are now 
in most work displaced by slate dowels or joggles. 
The pebbles are still sometimes used for small work. 


TOOLS AND APPLIANCES USED IN CUTTING AND 
BUILDING STONEWORK 

The tools used by the mason are many and varied, 
as different tools are required for different styles of 
work, and even where the same style of work is being 
wrought, but being made of softer or harder materials, 
other sets of tools will be required. Marble and the 
softer stones are worked with tools that are very much 
different from those used in working granite or the 
harder stones. 

The following tools and appliances are those mostly 
used at the present time by operative masons: 

Fig. I. The square is of various sizes, and generally 
made of steel plate about cne-eighth of an inch thick; 
the edges are parallel and at right angles to each 
other. 

It is important that the square should be true, as the 
accuracy of the work depends entirely upon it, and for 
this reason it should be frequently tested for correct¬ 
ness. 

Fig. 2. The set square is of several sizes, and made 
of iron, brass, or zinc plate; it contains a right angle 


202 


STONEMASONS’ GUIDE 



OOLS USED IN 

MASONRY 














































































TOOLS USED IN STONEWORK 


203 


and two angles of forty-five degrees, and is used ch\jfly 
for miters, and setting out on bed of work. 

Fig- 3* The bevel, or shift stock, made of iron or 
brass, and used for sinkings, bevels, etc. 

Fig. 4. A small tee square of unequal sides, and 
with right angles, used for sinkings, etc. 

Fig. 5. Mallet of beech, or other hard wood, of 
various sizes, for striking the cutting tools. 

Fig. 6. Hand hammer of steel, about five pounds in 
weight, used principally with punch for removing 
waste, and in very hard-grit stones. It is used also 
with hammer-headed chisels. 

Fig. 7. The punch; the cutting edge of this tool is 
about a quarter of an inch wide, and chisel-pointed. 
It is used with the hammer for removing all super¬ 
fluous waste. 

Fig. 8. The point, with edge similar to punch, is 
used with mallet, generally for hard-grit or lime 
stones, and for reducing the irregularities left from 
punch, leaving the stone in narrow ridges and furrows 
close down to face. 

Fig. 9. Chisels, of various widths, from ^ in. to 1% 
in. wide, used for mouldings, fillets, sinkings, etc. 

Figs. 10 and 11. Boasters, from 1^ in. to 3 in. wide, 
used for dressing stones down to smooth faces, and 
cleaning or finishing mouldings, etc. 

Fig. 12. Broad-tool, about 4 in. wide, used for 
tooling. 

Fig- 13. Claw-tool. These are of various sizes, the 
teeth being cut coarse or fine to suit the texture of 
the stone. For hard lime stones the teeth at point are 
about yi in. wide, and for softer stones from ^ to in. 
wide. The claw tool is used after the punch or point, 
dressing down the ridges still closer to finished face. 


204 


STONEMASONS’ GUIDE 


Figs. 14 and 15. Small chisels, of various sizes, for 
carving, letter-cutting, etc. 

Fig. 16. Small chisels, called “splitters,” of various 
sizes; the heads are concave, or cup-headed, as in 
sketch, Fig. 38. When used with an iron hamm-er, 
Fig. 21, they cut very smooth and sweet. 

They are used mostly for marble work, carving, 
lettering, etc. 

Fig. 17. Pitching tool; this has a beveled instead of 
a cutting edge, and is used with the hammer, for 
pitching or knocking off the irregularities or waste 
lumps on stone. 

Fig. 18. Jumper, chisel-pointed and slightly round¬ 
nosed; it is wider at cutting edge than the diameter of 
tool, so that it clears itself in cutting circular holes, 
for which it is used, chiefly in granite. 

Fig. 19. Chisel for soft stone (this is a general term, 
and comprises varieties like marble or alabaster). 
The chisels have wood handles, and are similar to car¬ 
penters’ “firmer chisels.” 

Fig. 20. Drags for soft stone, of best steel saw- 
plate, with coarse, middling, and fine teeth, called 
coarse, seconds, and fine drags. These are used by 
traversing the face of the stone in all directions and 
removing the saw and chisel marks, and finishing to 
any degree of smoothness required. 

Fig. 21. Iron hammer, about three or four pounds 
weight, used with cup headed tools, for carving, letter¬ 
ing, etc. 

Fig. 22. Dummy, of lead or zinc, about three or four 
pounds in weight, used for striking the soft sione 

Note—N umbers 8 and 15 are mallet headed tools, and 
must never be struck with the hammer, the heads being made 
to receive the blow of the mallet onlv. 



TOOLS USED IN STONEWORK 205 


tools; it is handier than the mallet, and at times more 
convenient to use. 

Fig. 23. Cross-cut saw, of best steel plate, and of 
various sizes, for cutting soft stone blocks, scantling, 
etc.; the teeth are coarse, and broadly set for clear¬ 
ance. Two men are required in using it. 

Fig. 24. Compasses, for setting-out work, etc. 

Fig. 25. Shows sketch of a saw frame, for hand¬ 
sawing, which in practice requires some little skill in 
framing up to the various sizes. 

The frame generally, for good working, should be 
about two feet longer inside than the length of stone 
to be sawed, so as to allow for draft. 

The heads or ends of frame are made of 4 x 3 in. 
pine, tapered from near the top to 3^ x 2 in. at the 
bottom, with a groove or slot for the saw 4 in. deep 
by 1% in. wide, the angles being rounded off or 
smoothed to make it easy for the hands. 

The stretcher is a piece of pole about 3 in. in diam¬ 
eter, with iron ferrule at each end, varying in length. 
Packing pieces are used against the head at each end 
of stretcher as shown. 

The couplings are in wrought iron, % in. in diam¬ 
eter, of various lengths and shapes, as in sketch 
These are tightened up with a union screw in the cen 
ter, which keeps the saw taut, so that no difficulty is 
experienced in getting the saw frame to the required 
length. 

The saw plate is of iron, about 4 in. wide by T V in. 
thick, with two holes punched through it, ^ in. in 
diameter, at each end, for iron pins, which are inserted 
to keep the saw in position. The pins are 4 in. long, 
and have a small slot the thickness of the saw plate 
and in. deep, fixed with the groove towards the end 


206 


STONEMASONS’ GUIDE 



SAW FRAMED UR 

















































TOOLS USED IN STONEWORK 207 


of the saw; this enables the sawyer to keep the saw 
straight down the cut, by tapping either end of the 
pin, should the saw deviate from the vertical line. 
This slot in the pins is important, as the saw cannot 
be kept true without this arrangement. The pole, for 
carrying the saw frame, is from 16 to 20 ft. long and 3 
or 4 in. diameter at bottom, and tapering towards the 
top; a crosspiece and chain is secured nearly at the 
top of pole to carry the pulley. The pole is kept in 
position by planting it in the ground, and a rough piece 
or two of stone is laid against it. The cords for carry¬ 
ing the saw frame are about ^ in. in diameter; small 
chains are sometimes used, but cords work more easily. 

The cord is fastened round the stretcher and over 
the pulleys on top of the pole (which must be vertical 
to the cut), and then round hook of bottom pulley. 
The weight must be so adjusted as to allow the saw- 
frame to be the heavier by about eight or ten pounds; 
this, however, will depend greatly on the nature of the 
stone. The position of weight can be raised or low¬ 
ered to suit the cut by shifting the cord at the bottom 
of the pole. 

The drip board is of pine, as in sketch, and about 2 
ft. long, with sloping side against the cut, and on this 
is placed the water tub; a small spigot is inserted in 
the bottom of the tub, and is adjusted to allow the 
water to trickle down the board, carrying with it the 
sand, which is also on the board, into the cut. To 
regulate the supply of water and sand, the sawyer uses 
a small rake with a long handle. 

The line of cut for saw should be set out with a 
plumb rule or bob at each end of the block, and a 
V-shaped chase cut in to guide the sawyer in keeping 
to a true line. 


208 


STONEMASONS’ GUIDE 


The best sand for cutting.is hard grit, washed 
through several sieves, all the coarse and fine being 
rejected, and the medium size only used. A bushel of 
this sand will cut about 12 ft. super of stone. 

The saw is drawn backwards and forwards and the 
stone cut by the attrition of the saw plate with the 
sand and water. 

A good sawyer can cut by hand from 15 to 20 ft. 
super of sandstone in one day of ten hours. 

On large jobs steam stone saw frames are used, in 
which, if necessary, from one to twenty cuts may be 
put in one block at the same time. 

Fig. 27. Shows a method of coping or splitting a 
block of stone to a required size. 

Begin by cutting a V chase on top and two sides of 
the block, as at g, f e\ directly under this place a 
wood skid, and on the top of the skid a long iron bar, 
which should bone with the line^/; or a punch driven 
in on each side, as at will do nearly as well. At 
extreme end place a short skid, as at h, and packed up 
to within an inch of the under side of the block. This 
is done to prevent the coped piece from breaking 
under by its own weight, as the fracture would not 
take the line of direction proposed, but would prob¬ 
ably break away from j to k and spoil the block. 

Sink wedge holes with the punch (at distances apart 
varying with the nature of the stone) to as fine a point 
as possible at the bottom of the hole, as in sketch, at 
b , so that the wedge will bite or hold when struck with 
the hammer. The apex of the wedge, which is of 
iron, is blunt pointed and about ^ in. wide, so that it 
does not touch the bottom of the hole, or when struck 
it would jump out. The holes being cut, the wedges 
are inserted in each one; care must, however, be taken 


TOOLS USED IN STONEWORK 


209 


to keep them upright, so that the cleavage takes the 
line of direction required. The wedges are now 
gently tapped with a heavy hammer, till all have got 
a hold; then harder blows are given in quick succes¬ 
sion, and the fracture takes place. 

a shows sketch of wedge, made of iron, and from 4 
to 5 in. long and I^ in. wide. ( 

In coping or splitting granite, wedge holes are not 
cut as in stone, but circular holes are “jumped,” 1 in. 
or 1in. in diameter and about 5 in. deep, at dis¬ 
tances apart varying with the obstinacy of the mate¬ 
rial, and plugs and feathers are inserted and driven in 
as for stone. The plug is of soft steel, and made 
tapering as at c . 

The feathers are thin pieces of iron, concave in sec¬ 
tion, as shown at c 1. These are first put in the holes, 
the plugs are then driven in until they become tight, 
and a few sharp blows are all that is necessary to com¬ 
plete the process of splitting, c 1 is a plan of c to a 
'arger size. 

Fig. 28 shows a pair of iron lewises used in lifting 
worked stones for fixing. The lewis consists of a 
dovetail of three pieces, the two outer pieces being 
first inserted in the hole, and then the center piece, 
which acts as a key, and tightens up the dovetail; the 
shackle is next put on, and the bolt is passed through 
the whole. 

Care must be taken to cut the hole to a dovetailed 
shape, and of the size of the lewis. 

A is the front view and B is the side view, of the 
lewises. 

Fig. 29. Shows an iron conical-shaped lewis plug, 
which is placed in a slightly larger dovetailed hole, a 
small curved iron plug being inserted by its side. 


210 STONEMASONS’ GUIDE . 

which keys it up. This is used chiefly for worked 
granite. 

Fig. 30. A pair of chain lewises, consisting of two 
curved iron plugs with rings for chain; these are 
inserted in a dovetailed hole, and when tightened up 
act similarly to the ordinary lewises. 

Fig. 31. A pair of iron dogs, or nippers, with steel- 
jointed claws, used for lifting rough blocks, and also for 
fixing. 

Fig. 32. Axe, about 12 or 14 lbs. in weight, chisel- 
pointed, used on granite for removing the inequalities 
left by the pick and dressing it similarly to tooled 
work in stone, showing the marks or indents in paral¬ 
lel lines. 

Fig. 33 * Pick, about 16 lbs. weight, used chiefly on 
granite, for dressing the inequalities of the rough or 
rock face down to within 1 in. of the finished face; 
and also used for scabbling blocks of stone roughly to 
the required shape. 

Fig. 34. Spalling hammer, about 12 to 14 lbs. 
weight. This has a square edge of about 1% in., and 
is a very effectual tool for knocking off rough lumps. 

Fig. 35. Patent axe; the body of this is of iron, with 
a slot at each end, into which a number of parallel 
thin plates of steel, chisel-sharpened and of equal 
length, are inserted and tightly bolted together. This 
is used for granite, and produces the finest description 
of face, next to polishing. 

Fig. 36. A pair of trammel heads, or beam com¬ 
passes, used chiefly for setting out arcs of circles ful' 
size; those made of gun-metal, with steel points, are 
the best, and a set should be large enough to take a 
rod 30 ft. long. 

Fig. 37. A spirit level for fixing. 


TOOLS USED IN STONEWORK 


2 11 


Trammel hcced-s k Root 



FIG 37 | ^ ~ ^ 



,t '-. 7 .' * 



C OP/AfC on S PLITTIN G BLOCK 

BY WEDGES 
















212 


STONEMASONS’ GUIDE 


The following appliances are also required for set* 
ting out work: 

A large platform or drawing board, about io or 12 
ft. square; or if larger than this, the better. It maybe 
fixed either vertically or horizontally. 

A standard five-foot rod. 

Two or three straight-edges of various lengths. 

Pine rods for story rods, and for setting out lengths 
of cornices^ modillions, dentils, etc. 

Pipe-clay and stiff brush, for cleaning off board, 
rods, etc. 

Sheet zinc for moulds, usually No. 9 gauge, this 
being a good workable thickness. The lines for face, 
bed, and section moulds have to be carefully trans¬ 
ferred to the sheet zinc, and cut to their proper contour 
or shapes with shears and files. 

The foregoing lists do not comprise all the tools and 
appliances required for every branch of masonry, but 
only those which are in common use. 

All cutting tools are made of the best cast steel, 
except the pick, axe, and spalling hammer, which are 
sometimes of iron, steel pointed and faced. 

NAMES OF WROUGHT STONE 

There are three classes of stones made use of for 
building purposes; namely, rough stones as they are 
taken from the quarry, stones squared and dressed in a 
rough manner, stones dressed and squared accurately. 

Stones, rough and left unsquared, are called “rub¬ 
ble.” When stones are roughly squared and dressed, 
they may be “quarry faced”; that is, the face is left 
just as it came from the quarry; or it may be “pitched 
faced,” or “rock faced.” in which case the face will 


NAMES OF WROUGHT STONE 


213 



project beyond the face of the joint; or it may be 
“drafted,” in which the face is surrounded with a 
chisel draft to allow of the joints 
being flush on the face. 

In cut and dressed stones, there 
are: 1, the rough pointed; 2, the 
fine pointed; 3, the crandaled; 4, 
the tooth axed; 5, bush hammered; 
B Eli U 6, rubbed; 7, diamond paneled. 

There are also other finished 
stones, that will be discussed in 
future pages. 

The illustrations (Fig. 39) show 
the different stones when finished. 

These exhibit the various forms 
of dressing stone commonly used. 

A shows a boasted or chiseled 
face, sometimes termed droved 
work. The face is finished with 
a boaster, and the strokes are 
generally regular and parallel to 
each other. 

In hard-grit stones this face is 
usually left as finished, and when, 
as in the case of a building, the 
whole of the ashlar and plain work 
is chiseled to the same angle of 
inclination, the effect is pleasing. 

In softer stones a finished face 
is formed by rubbing the boasted 
face with sand and water, and 
removing all chisel marks; it is 
then called plain ashlar. 

B shows ashlar with tooled face. 



jr v. T '*t 1 «. J 




Fig. 39 . 
















































214 


STONEMASONS’ GUIDE 


This is formed with a broad tool, or wide boaster, by 
a regular succession of strokes, parallel to each other, 
extending across the whole width of stone, and when 
finished shows a series of flutes or channels, the size 
of flutes depending on the texture of the stone. 

Considerable skill is required in tooling neatly, and 
the tooling is somewhat costly, the surface having first 
to be worked to a boasted face. 

C shows ashlar with pick or pecked face, and tooled 
margin. 

This is produced with a point, or in the case of 
granite with the pick, and can be worked to any degree 
of fineness. 

D shows ashlar with punched rock face, and tooled 
margin. 

This is similar to the last mentioned, but much 
coarser. In producing it, the punch is driven in 
almost vertical to the face until the stone bursts out, 
leaving a series of cavities. 'When regularly done it 
looks well, and is very effective, and for large work it 
gives the appearance of boldness and solidity. 

E shows ashlar with broached lace, and tooled 

margin. 

This is produced with a point, which forms a furrow 

with rough ridges, and is worked across the stone to 

the required angle. 

F shows ashlar with rusticated face, and tooled 

margin. 

This is worked with small chisels and points, and 
sunk down about half an inch, leaving a plain, narrow 
margin on face; the pattern is irregular, but easily 
adapted to any space. 

G is a rebated or rustic quoin, with vermiculated 
face. 


NAMES OF WROUGHT STONE 215 

This is cut out with small chisels, and has the 
appearance of being worm-eaten. 

In order to prepare the stones for dress finishing 
they must first be brought to a flat surface on one 
side. This flat surface or face maybe “winding,” or 
it may be a plain, flat surface similar to that shown in 
Figs. 40 and 41. 

When the bed, or 
one plane surface, 
has been produced, 
the required shape of 
the sides of the block 
are marked upon the 
surface with the aid 
of a square or tem¬ 
plate. Drafts are then 
sunk by the chisel across the extremities of an adja¬ 
cent face with the aid of a square (Fig. 40), or bevel if 
the sides are not to be at right angles to the bed, and 
a second face is obtained between such drafts. The 

process is repeated 
for the third face, 
and so on, until the 
block has been 
brought to the de¬ 
sired form. 

Regularly winding 
surfaces may be ob¬ 
tained in various 
ways. The simplest plan is when the stone is worked 
to the proper planes and angles, as just described, 
to set off the amount of the winding, Aa, Fig. 42, 
on the arris and draw the drafts, lines aB , aC. A 
series of lines, as be , cf dg , are then drawn parallel 



Fig. 41. 



Fig. 40. 










216 


STONEMASONS’ GUIDE 



with A a, and another series, eh,fi, gk, parallel to AC. 
The drafts being sunk at these, so that a straight edge 
coincides from b to h, or c to i, or d to k, the surface is 
wrought so that when the rule is applied parallel to the 
plane A a B, it may 
coincide with the sur¬ 
face at every point. If 
one end of the stone is 
less in length than the 
other, (Fig. 43), the line 
aB must be divided into 
equal parts, and the 
lines be, cf dg, drawn 
parallel to A a. The 
line CD is then divided 
into the same number 
of equal parts in h, i, k\ then ch, fi, gk are joined in¬ 
stead of being drawn parallel to AC. The drafts are 
then sunk unlil a straight edge agrees from b to h, and 

so on, and then the sur¬ 
face is dressed so that 
B the straight edge will 
coincide in a direction 
parallel to the plane 
A a B. 

Winding surfaces may 
likewise be formed by 
the use of two rules, one 
having parallel and the 
other divergent edges. 
These are sunk in drafts 
across the two ends of 
the stone until their upper edges are out of winding. 
The ends of these drafts are then connected by means 



Fig. 43- 








NAMES OF WROUGHT STONE 


217 


of two others formed along the sides of the block, 
and the entire surface worked down to them until 
it coincides with a straight-edge placed in a direc¬ 
tion parallel to the drafts. The rules used in this proc¬ 
ess are known as “twisting rules,” one of which, as 
at A, Fig. 44, is, of course, simply a straight edge 
with parallel to opposite edges. The other, B, is 
termed a “winding strip,” and that portion of it which 
coincides with the twist of the stone, as shown by the 
dotted lines, is, of necessity, a triangle. 

The formation of 
mouldings, columns 
and the work of the 
carver and sculptor, 
as well as that of the 
marble mason and 
statuary, form a spe¬ 
cial branch of the 
trade, which com¬ 
prises the production of such parts as enriched cor¬ 
nices, capitals, etc , and is necessarily valued by the 
time expended upon it; the value of the time varying, 
in the higher class of carvings, with the artistic repu¬ 
tation of the man employed, and, as this work is not 
intended to teach the higher artistic phases of the art 
of masonry, such matter will be left to be dealt with 
in another volume that may follow this in the near 
future. The wall mason builds all stone constructions 
and, from the irregular shapes and sizes of the mate¬ 
rials generally at his command for building purposes, 
is constantly called upon to exercise an amount of 
judgment and skill far beyond what is required to 
make a good bricklayer, who mostly lays his regular¬ 
shaped bricks according to fixed rules, which he knows 










218 


STONEMASONS’ GUIDE 


by heart, and ought not to depart from. The rougher 
the materials, the more skill is required in putting 
them together; whilst the greater the labor expended 
in dressing them to regular shapes, the easier is the 
task the wall mason has to perform. 

Large face moulds are sometimes made of several 
pieces of timber framed together. 

When the beds of the courses are to be plane and 
level they can be set correctly by the level and com¬ 
mon straight-edge. When they are to be planes hav¬ 
ing a given shape a rule must be employed having two 
straight edges inclined to each other at such an angle 
that, when one edge is set horizontal by the spirit- 
level, the other has the proper inclination. If the beds 
of the courses are to be perpendicular to a straight or 
curved battering face, their position can be set out and 
tested by the square. 

Curved beds, such as are employed for some special 
purposes, require the use of suitably curved bed moulds. 

In all cases in which economy of time and money 
has to be studied, the workman should, as far as prac¬ 
ticable, avoid curved figures in masonry; for not only 
are they more tedious and expensive to set out, and to 
build than straight and plane figures, tut it is more 
difficult to test the accuracy with which they have been 
executed. A single glance will detect the small¬ 
est appreciable inaccuracy in a wall with a straight 
batter, while the same process in the case of a wall 
with a curved batter, would require either a long 
series of measurements, or the application of cumbrous 
face-mould to various parts of the wall; and this 
becomes a matter of serious importance in large struc¬ 
tures, where errors in form may affect the strength and 
stability. 


NAMES OF WROUGHT STONE 


219 

All stones, except under peculiar circumstances, 
should be laid on their natural or quarry beds , or with 
their natural beds as far as possible perpendicular to 
the pressure they have to bear. The strength and 
durability of the stone depends on this being done— 
even in cases in which the natural beds cannot be dis¬ 
tinguished by an unpracticed eye—for few stones will 
bear the same pressure applied in the direction of their 
lines of stratification as at right angles to them; more¬ 
over, if the bed of a stone is exposed on the face of a 
wall, the water will get in between its layers, and frost 
will soon cause layer after layer to peel off; hence it 
follows that in projecting undercut mouldings and 
weathered coping the natural beds should be placed 
parallel to the side-joints. 

The careful bonding of the masonry must be attended 
to. A wall built of the roughest stones ought to be 
perfectly stable, though no mortar is used. 

The principles of bond, by the stones overlapping 
and breaking joint throughout the wall, are the same 
as in brickwork, and should be thoroughly understood 
by the mason, for upon their skillful application his 
reputation as a good waller depends. 

All dry and porous stones should be well wetted 
before being laid in mortar, so as to absorb the mois¬ 
ture required for the proper setting of the mortar. 

All joints should be filled up solid with mortar. 

The thickness of the bed-joints, depending' on the 
smoothness of the beds, must be sufficient to prevent 
any unequal bearing resulting from actual contact 
between any irregularities on them. 

Where a good appearance is aimed at, all stones 
exposed to view should be selected free from stains, 
chiefly caused by oxide? of iron. 


220 


STONEMASONS’ GUIDE 


Iron should never be placed in contact with stone¬ 
work where, by rusting, it might disfigure it with 
stains, or split the stone by its increase in bulk during 
the process of oxidation, or by its expanding and con¬ 
tracting under the influence of heat and cold. 

In order to understand the practical operations of 
building in stone, it is necessary to explain the differ¬ 
ent descriptions of masonry in ordinary use. These 
may, as before explained, be included under one of 
the three following heads, viz.: Rubble, Block-in¬ 
course, Ashlar. 

If the stone at disposal is thinly bedded, rough or 
intractable, it should be used as rubble-work; if obtain¬ 
able in blocks, and more or less easily wrought, it 
should be used as block-in-course, or ashlar , according to 
circumstances. 


RUBBLE MASONRY 

In rubble-work stones of irregular size and shape are 
laid in a wall, after having been more or less assorted, 
roughly shaped to fit one against another, and hammer- 
dressed on their faces with the waller’s hammer, 
according to the quality of the work required. 

In the rougher kinds of rubble-work no selecting of 
the stones takes place, but the waller, having once taken 
one up, places it in the wall as it will lie best, pack¬ 
ing in smaller stones between the larger ones. The 
stones should be placed on their best beds, and not on 
their points, which would be liable to crush, in addi¬ 
tion to the wedge-like action of such stone, in the 
interior of a wall, tending to dislodge the facework. 
No attention whatever is paid to the joints being more 
horizontal or vertical than naturally results from the 
bedding and cleavage of the stone used, upon which 


RUBBLE MASONRY 


221 


the degree of regularity in the appearance of the work 
mainly depends. 

In rubble masonry the rough nature of the work 
leaves many spaces between the joints, both on the 
face and interior of the wall; these should be carefully 
packed up or pinned with spalls, which are the pieces 
knocked off the rougher stones in order to get them 
to fit into place. 

Care should be taken that the hearting or interior of 
a rubble wall is well packed with spalls and mortar, 



Fig. 45. 


and not left full of hollows or mortar alone; to ascer¬ 
tain whether this has been done, take the waller’s 
trowel and plunge it in different places into the heart 
of the wall. 

The spalls must not be placed in the heart of the 
wall so as to drive like wedges when the weight from 
above comes on them, or the facing stones will be 
forced out. 

Attention is necessary during the building of rubble, 
as well as all masonry walls, to insure their being well 
bonded transversely, and not built up with two thin 




















222 


STONEMASONS’ GUIDE 


/// y y/ 





Vs ^ 


/ 


?/ 


scales on each face, tied together by through stones, 
with the core or hearting merely filled in with small 
pieces. This is a very common fault with masons, 
who will rely upon the mortar to give stability to a 
wall which, without it, would fall to pieces under its 
own weight. 

The best stones for rubble masonry are those that 
scabble freely, and such as lie in 4 or 5-inch beds. 
Basalts and stones 
of a crystalline 
structure are 
troublesome to 
use, as they fly 
under the hammer, 
but granite and 
sandstones work 
in well. 

Rubble may be 
either tmcoursed , 
irregular or random 
coursed , worked up 
to courses , or 
coursed , chiefly de¬ 
pending upon the 
character of the 
stone at disposal. 

Some stones, from 
their intractable 

nature, and the absence of any distinct lines of bed¬ 
ding, are especially adapted for uncoursed rubble 
(Fig. 45), whilst other stones have lines of layers or 
courses and therefore should be used in square rubble, 
as shown in Fig. 46. 

A portion of a structure in random rubble is shown 



s / ^ 

S' 

/ 

-/A ^ 










0 % 


■V y// / 


_ 

y*/ / /?//* 

/ ' /// 

y 

// y/ /S 


/// y/ 


Fig. 46. 













































RUBBLE MASONRY 


223 


in Fig. 47. This shows the quoins or corners in vari¬ 
ously finished stones, all of which are named on the 
illustrations. 

Random, common or rough rubble, built up to 
courses, is indicated in Fig. 48; the courses vary in 
depth from 12. to 18 inches. The remarks made 
above apply to this discription. 



Square uncoursed, random coursed, irregular 
coursed, snecked or squared rubble, are five names 
implying practically the same description of work. It 
is shown in Fig. 49, A. There is a certain amount of 
coursing, but it is not regular or continuous; jumpers 
are used, but no spalls, and, if careful attention can be 
















































224 


STONEMASONS’ GUIDE 


given to bond, the strength of the wall is considerable. 

Random with hammer-dressed joints and no spalls 
on face, or close-pricked polygonal ragwork, often 
called “cobweb” rubble, is shown in Fig. 49, C. Joints 
lie in all directions and considerable skill and experi¬ 
ence are required to make good work. Freestone is 
seldom used in this description of walling, as it is 
chiefly formed with broken boulders, or field stones 
that have been split apart by dynamite or other 
explosives. 



Fig. 48. 


Regular coursed rubble (Fig. 49, D)—a very perfect 
bond can be obtained in this class of work. The 
courses often vary in depth, but are seldom more than 
9 or 10 inches deep. Good stone found in thin beds in 
the quarry is commonly used. 

Joints in any of these examples may be galleted by 
driving into them, from the face, chips of flint or hard 
stone. 

Technical terms in connection with walling differ so 
much in different parts of the country that it is often 
advisable to build a small sample for reference in 
pricing quantities. 

In the rougher descriptions of rubblework, lacing 


















RUBBLE MASONRY 


225 


courses are used to give the wall additional cohesive 
strength; they are two or more well-bonded courses of 
masonry or brickwork laid at short vertical intervals. 

Block in course, or hammer-dressed ashlar (Figs. 
50, A, and 51, A), is intermediate between the best 
rubble and ashlar. The coursing is regular, and the 



O. n 2* 36 4860 


Fig. 49. 

blocks are roughly squared; it is frequently constructed 
of shoddies, which are sound stones less than 12 inches 
deep. The length of each stone should be from three 
to five times its depth, and the breadth from one and a 
half to twice its depth. The exact proportions depend 
on the degree of resistance which the stone offers to 









































226 


STONEMASONS’ GUIDE 


cross breaking. The same rules as to proportions 
apply to ashlar work 

Ashlar is in large blocks, squared and regular in size, 
laid in courses varying in depth from about io to about 
14 inches; the bed joints should be out of winding, but 

not smooth, and should 
never be worked slack 
(hollow on bed) and 
underpinned with spalls, 
as in Fig. 55,B; such a 
practice concentrates the 
weight on a small area, 
and leads to crushing or 
to the joints flushing, that 
is, the arrises breaking. 

Joints should be as thin as the class of work allows, 
but never so as to leave an insufficient cushion of mor¬ 
tar to spread the pressure over the whole joint, as. 
this would lead to flushed joints. Sheet lead has 



Fig. 5i,B. Fig. 52,B. 

been inserted in joints subject to great pressure, to 
equalize it; but it is found that it squeezes outward 
and flushes the joints, thus more than counterbalancing 
any good it may do. 

When the courses throughout the face of the build- 



Fig. 51,A. 















































RUBBLE MASONRY 


227 


ing are all of the same depth, the ashlar is regular 
coursed (Figs. 52 and 53). If they vary in depth, it is 
irregular coursed; if the courses are not continuous, 
but broken, it is random ashlar, but the last class of 
work is unusual. The bond 
adopted follows the general 
idea of Flemish, but as all 
stones are not of the same size, 
considerable freedom is allowed 
in bonding, and, except in the 
best class of work, no attempt 
is made to keep the perpends. 

The courses should range with 
the quoin stones and dressings. 

Joints can be made less than 
one-eighth inch thick. Plasterer’s putty is frequently 
used to make the outer part of the joint; it extends 
inward about two inches. Before being set, each stone 





Fig. 53.A. 


is laid dry in its place to ascertain that it truly fits. 
The amount of work on the face of ashlar varies very 
considerably; a drafted margin round a rough face is 
the minimum. 


























































































228 


STONEMASONS’ GUIDE 


Rebated joints and V-joints are shown in Figs. 55,B, 
54,B, and 55, B. They are used to emphasize the joints, 
and at the same time they prevent them from flushing. 

Ashlar, so treated, is called rusticated. 

A wall built of solid ashlar is necessarily costly, and 
the term has come almost to imply a facing of ashlar 
with a backing of rubble or brickwork. The ashlar is 
often only four inches and seldom more than six inches 
[thick, with bond stones projecting into the backing. 


Fig. 55,A. Fig. 55,B. 



Fig. 54, B. 


Figs. 52 and 53, A, show examples of brick ashlar and 
rubble ashlar. The ashlar should average about 8 
inches on the bed, and should bond transversely with 
the backing. Headers of a length at least two-thirds 
of the thickness of the wall should be laid, one to 
every superficial yard of face. The backing, if of 
rubble, should be built in courses, each leveled up to 
















































































































RUBBLE MASONRY 


229 


coincide with the ashlar courses. If of brick, the ashlar 
courses must be of suitable depth to allow of the same 
treatment. The greater number and greater thickness 
of the joints in the rubble or brickwork lead to more 
compression in the backing than in the facing, and 
this tends to cause the wall to bulge outward. This 
effect can be to a large extent avoided by building in 
cement or a quick setting mortar. Badly built walls 
of this description are very liable to collapse in case 
of fire, owing to the differing behavior under heat of 
the back and face. 

Some may be roughly squared at the quarry; it is 
then said to be hammer dressed or quarry pitched. 
Afterward it is sawed to size, half sawing being charged 
to each of the two blocks produced by one cut. Saw¬ 
ing is now largely done by machinery. Plain work is 
the labor on a stone to “take it out of winding,” or 
reduce it to a plane surface. Half plain work is simi¬ 
lar, but is more roughly done, as for beds and joints. 
Self faced, natural faced, rock faced, are terms all of 
the same meaning, and indicate that the face of the 
stone is left rough as from the quarry, though it may 
have been scabbled with the hammer to remove irregu¬ 
lar projections. A wall built of natural faced stone 
sometimes is called rustic face (see quoin stone in Fig. 
47), but it must not be confounded with the rusticated 
joints mentioned above. 

A stone is taken out of winding by cutting with the 
chisel a drafted margin along each edge of its face, 
as shown, and by means of a straight-edge bringing 
them all into a plane; the intervening space is then 
worked down to the same plane. If the plane surface 
be obtained by means of a point instead of a chisel, it 
is called pointed work; the drafted margin is, how* 


230 


STONEMASONS’ GUIDE 


ever, first made with the chisel. When the chisel 
marks are parallel and regular, but not continuous 
it is called boasted or droved work; when they are 
parallel, regular, and continuous, it is called tooled 
work. Stroked work is similar to the last, but the 
lines make an angle of 45 degrees with the edge. Soft 
stones are taken out of winding with a comb or drag, 
which often is merel}' a piece of a joiner’s saw. 

Rubbed work is plain work rubbed to a smooth sur¬ 
face; a rub stone is used with sand and water for this 
purpose. Some stones, such as marble, can afterwards 
be polished to a glassy surface. Vermiculated work is 
indicated in Fig. 39. Sunk work is any cutting below 
the plain surface, as in rebating or weatherings. 
Circular work is the labor required to form convex sur¬ 
faces, as the shafts of columns. Circular sunk work is 
the labor required to form concave surfaces, as in 
stone channels. Circular circular work is the labor 
required to form such a surface as a sphere or a basin¬ 
shaped hollow. Moulded work is when a moulding of 
any profile is worked on the edge of a stone, as the 
cornice in Figs. 49 and 52. Circular moulded work is, 
in bills of quantities, always kept separate from 
straight, and is charged at a higher rate. Work is 
called stopped when the labor, whether sunk or 
moulded, is not continuous to the end of the stone, as 
the chamfer on the stone head in Fig. 49. 

Quoins may be built of larger or differ ntly worked 
stones from the remainder of the wall. A brick quoin 
may be built to a rubble wall, and more rarely to ashlar 
work, as in Fig. 51. In some varieties of rubble it is 
almost impossible to construct a sound quoin unless 
material superior to the bulk of the wall be used. 

Ashlar work is constantly used for the dressings to 


RUBBLE MASONRY 


231 


windows and doors in brick and rubble walls; Fig. 47 
is an example. Reveals with recesses may be formed 
as in Figs. 50 and 51. 

Stone window-sills for sashes and casements should 
be set to project about 2 inches from the wall face; 
they are weathered and throated, so that rain-water 
may run off the surface and drop clear of the wall 
beneath. They may be moulded on the front, and 
stools are worked on the ends for the brick or stone 
jambs to rest on. 

To prevent water from being blown in between the 
stone sill and the wood sill resting on it, a water- 
tongue, usually of galvanized iron, iyi in. by % in., is 
set in a groove in the stone and wood; it and the wood 
sill should be bedded on the stone with white lead 
ground in oil. If sills are set flush with the wall, a 
separate drip mould (Fig. 47) should be fixed imme¬ 
diately below to serve the purpose of a throating. 

Window-heads are made as wide on the bed as the 
reveal; the head of frame is behind them, with lintel 
(with or without relieving arch) over. A separate drip 
mould over the head, as in Fig. 47, protects it from 
water stains from above. 

Coping stones are made in many forms, and are 
often handsomely moulded. As their purpose is to 
keep wet out of the wall, they should be chosen as 
nearly impervious to moisture as may be, cut in long 
lengths, say 5 feet or so, to reduce the number of 
joints, weathered and throated, and set and jointed in 
cement. These are respectively parallel saddle-back, 
and feather-edge coping; the first should only be used 
in inclined situations, as on gable walls. Raking 
copings are prevented from sliding by dowels built 
into the bed on which they rest. The same object k 


STONEMASONS’ GUIDE 


132 

served by kneelers, which are coping stones provided 
with horizontal tails (Fig. 47). There may be several 
of these in a large gable. Those at the foot are some¬ 
times in the form of corbels (Fig. 47), when they are 
called skew corbels. The large triangular stone at the 
head of a gable (Fig. 47) is variously called summer 
stone, saddle stone, or ridge stone. 

A cornice at the head of a wall (Figs. 49 and 52) may 
be one or more stones in height, moulded in front, 
and weathered and throated. There should always be 
sufficient tail weight for the stone to rest in its place 
without the assistance of the cement mortar in which 
it is bedded and jointed. Vertical cramps, say 2 in. 
by Y in., 4 or 5 feet long, and one to each length of 
stone, or a blocking course, may be added to increase 
the stability. 

In addition to mortar or cement, special connec¬ 
tions, such as cramps, dowels and joggles, may be 
adopted for binding stones together; these terms are 
used rather loosely and sometimes interchangeably. 
A cramp is a connecting piece of metal, slate, or hard 
stone, so shaped that it holds two stones together. 
A dowel is a short, thick pin or narrow plate of metal, 
slate or stone, fitting into two sockets; it is sometimes 
called a plug, especially when fixed in the bed joint, or 
when it is formed by running molten lead into a dowel 
hole. Joggle is a comprehensive term, and include* 
all cases where a projection on one stone fits a cor¬ 
responding sinking in the next. 

Regular coursed rubble, as shown in Fig. 56, is 
applicable where the beds, though thin, are pretty 
regular, so that a sufficient number of stones of a uni¬ 
form depth can be got to allow of their being laid in 
regular courses of one stone only in depth. 


RUBBLE MASONRY 


233 


Dry rubble walling is the simplest class of rubole 
work, and consists of stones roughly hammered, and 
bedded by pinning spalls, without any mortar. It 
requires considerable skill to lay a wall up of this kind 
and keep it up straight and fair on both exteriors. 



Fig. 56 . 


This kind of a wall should be wider at the base than at 
the top or coping. They are generally built to lines 
strained through trestles or horses, as shown in Fig. 
57. This saves much time, as it avoids the necessity 
of plumbing the faces. 

Dry rubble walling is generally built in courses about 



Fig. 57- 


12 inches high, and should have a water proof top, or 
coping, to keep the water from' getting into the body 
of the work and bursting it in frosty weather. The 
coping may be made of stones laid on edge in mortar 
(Fig. 58) of bituminous concrete, or, for want of any« 
thing better, clay puddle, o r even sods. 




























234 


STONEMASONS’ GUIDE 


Rubble ashlar consists of an ashlar stone face witV 
rubble backing (Fig. 59), and is subject, even to a 
still greater extent than brick ashlar, to the evi ; 
caused by unequal settlement. 

To avoid these 
evils, the stones and 
joints of the rubble 
backing should, as 
before mentioned, be 
made as nearly as 
possible of the same 
thickness as those in 
the ashlar facing, or, if the joints are necessarily 
thicker, there should be fewer of them, so that the total 
quantity of mortar in the backing and face may be 
about the same. This can seldom be economically 

arranged in practice, 
but it should be re¬ 
membered that the 
more numerous and 
coarser the rubble 
joints, the worse 
the construction be¬ 
comes. 

The ashlar should 
be bonded in with 
through stones or 
“headers,” as pre¬ 
viously described; 
their vertical joints 
should be carefully 
dressed for some distance in from the face, and their 
beds should be level throughout; the back joint and 
sides of the tails of the stones may, however, be left 



Fig. 59. 













RUBBLE MASONRY 


235 


rough; the latter may even taper in plan with advan¬ 
tage, and they should extend into the wall for unequal 
distances, so as to make a good bond with the rubble, 
the headers from which should reach well in between 
the bond stones of the ashlar. 

Through stones may be 
omitted altogether, headers 
being inserted at intervals on 
each side, extending about 
two-thirds across the thick¬ 
ness of the wall. 

Care must be taken that 
the stones in the ashlar fac¬ 
ing have a depth of bed at 
least equal to the height of 
the stone. In common work 
the facing often consists merely of slabs of stone hav¬ 
ing not more than from 4 to 6 inches bed, with a thin 
scale of rubble on the opposite side, the interval being 

filled in with 
small rubbish, 
or by a large 
quantity of mor¬ 
tar, which has 
been known to 
bulge the wall 
by its hydro¬ 
static pressure. 

The ashlar 
facing is in all 
respects, except 
those above mentioned, built as described in the sec¬ 
tion on ashlar, and the backing may be of random 
rubble done in courses from 10 to 14 inches high, 











236 


STONEMASONS’ GUIDE 


according to the depth of the stones in the facing. 

The illustration, Fig. 59, shows the section of a wall 
3 feet thick, with an ashlar facing composed of good 
substantial stone. 

Irregular rubble, as before stated, is built up with 
split boulders, and when finished has an appearance 
as shown at Fig. 60. When a good face is formed and 
nice joints made, this kind of walling presents a very 
fine appearance. 



Fig. 62 . 


Coarse rubble without dressed quoins has an appear¬ 
ance similar to that shown in Fig. 61. 

Snecked rubble is a method of building in which 
almost any size of dressed stones may be used. The 
stones marked Fig. 62, are jumpers, B are bonders, and 
S are snecks. Jumpers must not be used too freely in 
a wall of this description, or the wall will collapse, 
especially if any great weight is placed on the top of 

















































































RUBBLE MASONRY 


237 


the wall. Bonders should be even/y distributed 
throughout the whole wall in order to strengthen it, 
the name bonder showing that the stone goes through 
the wall to the inner face. Snecks, which determine 
the name of the wall, should be built in as often as 
possible. In a block joint two stones are butted 
against two stones, or two stones are butted against 
three stones (Fig. 63); or the stones are butted against 
each other without any attempt at bonding or breaking 
the joints. 


nn 


3 


EZZ 


Fig. 63 . 


Fig. 64 . 



—r 

-r-71—r* 

-LV- 1 

!. 1 r J -| Mr 1 


In Fig. 64 a common arrangement with single snecks 
beside each jumper is shown. In engineering works 
on a large scale, this is frequently done where a 
masonry wall has to resist forces likely to overturn, or 
having a tendency to overturn, the whole mass, or a 
part of it. It is claimed that the snecked work is 
stronger than coursed 
work, inasmuch as each 
jumper forms a vertical 
tie between two courses, 
and tends to prevent 
a too long horizontal 
course from yielding as 
a hinge. 

Some engineers seem to consider that single snecks 
place the jumpers too near to one another, and thus 
probably form a diagonal line of rupture. An arrange¬ 
ment like Fig. 65 may thus be preferred by some, giv- 



'1 1 ‘ i I 1 "T 

1 1 


I 


1 1 

1 \ 

1 

i 1 11-1 L 


Fig. 65 . 










































238 


STONEMASONS’ GUIDE 


ing a short course instead of a single sneck between 
each pair of jumpers. 

Several of the vertical joints in Fig. 65, are badly 
arranged, tending to become perpends. Joints nearly 
vertical over one another should be separated either 
by a jumper or, if at all possible, by two ordinary 
courses. 

A fault of some of the work executed is that it 
seems more like brickwork than masonry. There 
ought never to be the rigid regularity of brick bond in 
the face of a masonry wall. The regular irregularity— 
if we may so term it—of a well-built wall shows the 
skill of the craftsman, and is even appreciated by 
those able to judge as the correct placing and true 
economy of every cubic inch of material which the 
workman has had at his disposal. 

Bond.—The best bond in masonry is that which 
shows on the face of the work alternate headers and 
stretchers in each course, as in Flemish bond in brick¬ 
work, each header coming over the center of a 
stretcher in the course below. In such work one-third 
of the face consists of headers, if the length of the 
stretchers is twice the breadth of the headers; but as 
stones are rarely cut to exactly the same dimensions, 
it may be laid down that not less than one-fourth of 
the face of the wall should consist of headers and that 
the stones should break joint from once to one and a 
half times the depth of the course. 

Joints.—The thickness of the joint will vary from 
one-half to one-eighth of an inch, according to the 
smoothness of, or amount of work bestowed upon, the 
beds, as it must be sufficient to transmit the pressures 
from stone to stone, without permitting of actual con¬ 
tact at any point of their surfaces. The mason’s joint. 


RUBBLE MASONRY 


239 

or a properly struck joint, is the best which can be 
used. 

Flush Joints.—Care should be taken to prevent the 
use of flush joints, which are formed by hollowing the 
beds below the plane of the chisel draughts run round 
the edges. This was sometimes done by the Greeks, 
in order to get perfectly close joints; but, by throwing 
all the pressure on the edges of the stones, they fre¬ 
quently splinter off and spoil the look of the work. 

As flush joints cannot be detected after the stones 
are laid, the masons must be well looked after while at 
work upon them. 

With a view of guarding against the splintering, or 
spalling , of the arrises of cut stonework, as in columns 
carrying heavy weights, seven or eight pounds sheet- 
lead is frequently placed between the stones. The 
lead, which is not allowed to reach within less than 
one inch of the edges of the stones, is thought to 
equalize the pressure over the beds by yielding to any 
slight irregularities on them, but the use of lead 
instead of mortar is a great mistake. It has been 
found that stones bedded on thin pieces of pine, instead 
of lead, equal in area to the bed-joint, bore a greater 
crushing force than stones double their sectional area 
bedded on lead in the usual way. The lead which had 
been used showed no signs of accommodating itself to 
the irregularities of the beds. 

The joints of stone columns are often raked out 
about one inch deep, and pointed up when there is no 
longer any fear of their settling. The arrises of stones 
are also prevented from spalling by cutting them back, 
though this is generally done merely to give a bolder 
effect to certain parts, such as the quoins and lower 
stones of buildings. 


240 


STONEMASONS’ GUIDE 


Open Joints.—Open joints, resulting from projections 
beyond the plane of the chisel draughts, must also be 
avoided, especially in the beds, as tending to dis¬ 
tribute the pressure unequally over them. 

Rusticated Joints.—Rustic work properly applies to 
facework left rough from the hammer, though it also 
applies to a debased class of masonry, 
picked into deep holes, or honeycombed 
all over, to give a rough effect; but the 
term rustication, or rusticated, is also 
much used to denote masonry in which 
the joints are either chamfered, or sunk 
square below the facework. 

Saddle or Water-Joints.—In addition 
to the slopmg off or weathering of the 
upper surfaces of stonework exposed 
to the rain, as in coping , cornices, and string courses, 
it is well to saddle the joints, by leaving them rather 
higher than the rest of the work, as in Fig. 66, in order 
to throw the rain away from the joints, and so prevent 
any water finding its way through them, and down the 
face of the work. Such joints are called water-joints . 

Rebating.—The adhesion of mortar or cement, and 
the weight of the stones themselves, cannot always 
be relied upon as affording 
sufficient stability to stone¬ 
work, especially when not 
built into the body of the work, 
where they would be held in 
place by the superincumbent weight; hence different 
methods are resorted to in order to give additional 
stability, such as rebates, joggles, cramps, lead plugs , etc. 

A rebated or lap joint (Fig. 67) is formed by cutting 
away a portion of the edge of each stone, so as to 



Fig. 67. 



Fig. 66. 










RUBBLE MASONRY 


24} 


allow them to lap over each other. Fig. 68 shows the 
proper way of making a rebated joint on a slope, as in 
the case of a barge course or coping on the gable end 
of a building; water is thus effectually kept out, which 
would not be tne case if the side a were uppermost. 

Joggling.—Stones are said to be joggled together 
when prevented from sliding by a projection ox he-jog¬ 
gle, on one stone, fitting into a 
corresponding notch, or she joggle, 
in the other stone (Fig. 69). 


Fig. 68. Fig. 69. 

The he-joggle is generally cut square, and should 
taper slightly from the shoulder to the end, being 
stronger and easier to cut and fit into place when sc 
made. If, instead of one or more square joggles, the 
joggling is continued along the joint, it becomes a 
tongued and grooved joint 


Fig. 70. Fig. 71. 

Doweling.—The above methods, except in special 
cases, as in Fig. 68, are wasteful both of labor and 
material; a better plan, therefore, is to sink, exactly 
opposite each other, two she joggles or dowel holes , one 
in each stone, either circular or square in section, and 
fit into them a dowel or pin (Fig. 70), either of some 


































242 


STONEMASONS’ GUIDE 


hard stone, such as greenstone, granite or slate, oi 
brass, zinc, or copper. 

Copper dowels are the best, but very expensive; iron 
are the strongest, but should not be used unless per¬ 
fectly secured from air and moisture, for fear of their 
cracking the stone during the process of oxidizing, 
and as an additional precaution they should be thor¬ 
oughly tinned or galvanized. 

There is nothing, perhaps, better, on the whole, than 
good hard slate dowels run with brimstone or cement. 

Where very perfect workmanship is required, as well 
as when placed so as not to admit of being run in, the 
pins are made to fit the 
dowel holes accurately, 
being slightly tapered 
towards the ends, to 
secure a good fit and 
facilitate the setting of 
the stones. 

Lead Plugs.—In con¬ 
necting stones by means 
of lead, plug holes, which may be dovetailed if thought 
necessary, are made, one in each stone, exactly opposite 
each other, as in Fig. 71, with a channel leading to them 
from the top of the joint, through which molten lead is 
run into them. The bottom of the plug holes should 
slope downwards, so as to carry the lead into them at 
once, as well as to give the stone a more secure hold of 
the lead. Great care should be taken in running in lead 
that there is no moisture in the holes, whicn, if suddenly 
converted into steam, might cause a serious accident. 

Dovetail Bonding. —In masonry constructions in¬ 
tended to resist the shocks of waves, in addition to the 
methods given above, the stones may be held in posi- 





RUBBLE MASONRY 


243 


tion by being dovetailed one into the other (Fig. 72), 
as was done by Smeaton at the Eddystone lighthouse: 
but good cement and dowels would no doubt be 
equally efficacious, and at the same time less expensive. 

Tabling. —Stones of different courses may also be 
given great resistance to lateral shocks by tabling (Fig. 
73), in which a flat projection cut on the bed of one stone 
fits into a corresponding sinking in the bed of the one 
under or overlying it. This method, however, is 



Securing Bolts, etc., in Stonework. —Iron bars and 
bolts are generally secured in stonework by being 
enlarged or jagged at the ends—bolts so made are 
called rag-bolts —let into dovetailed holes in the stone, 
and run with lead (Fig. 74). Brimstone is often pre¬ 
ferred to lead, being cheaper and less liable to loosen 
by expansion and contraction. 

Protecting Cut Stonework.— Any projecting or carved 
stonework in a building should be boxed up with 
rough boarding, after it has been set, to guard against 
its being injured by the carelessness of workmen, or by 
bricks, etc., falling from the scaffolding, during the 
progress of the work. The treads and nosings of steps 
should also be boarded over for the same reason, as 
well as to protect them from the rough traffic. 

All the cut stonework should be well pointed and 
cleaned down before the building is given over for use. 











244 


STONEMASONS’ GUIDE 


ARCHES AND JOINTS 

In the first part of this work, designs for many kinds 
of arches were given and described, and the rules 
given are in many cases applicable for stonework; so I 
will not burden this part with many examples, as those 
already exhibited, along with the few presented here¬ 
with, will be ample to serve the purposes of most 
workmen, and before proceeding further, it may not 
be out of place to explain a few of the terms that are 
made use of in connection with the construction of 



The under surface or soffit is called the intrados , and 
the outer surface the extrados. 

The voussoirs are the separate arch blocks composing 
the arch, the central one being the keystone. 

The springers are the first or bottom stones in the 
arch on either side, and commence with the curve of 
the arch. 

The skewbacks generally apply to segmental arches, 
and are the stones from which an arch springs, and 
upon which the first arch stones are laid. 









ARCHES AND JOINTS 


245 


The span of the arch is the extreme width between 
the piers or opening; and the springing line is that 
which connects the two points where the intrados 
meets the imposts on either side. 

The radius is the distance between the center and 
the curve of the arch. 

The highest point in the intrados is called the 
crown , and the height of this point above the spring¬ 
ing is termed the rise of the arch. 

The center is a point or points from which the arch 



is struck; and lines drawn from this center or centers 
to the arch are radiating joints, and are also called 
normals. 

All joints in arches should be radii of the circle, 
circles, or elipses forming the curve of the arch, and 
will therefore converge to the center or centers from 
which these are struck. 

Fig. 75 shows a segmental arch, in which the above- 
mentioned terms are illustrated. 

Fig. 76 is a semicircular arch, AB being the span and 
CD the rise; the left-hand half has the ordinary joints 
radiating from the center C, and the right-hand half, 


























246 


STONEMASONS’ GUIDE 


with rebated or step joints, also radiating from the 
center C. This last is a sound and effective joint where 
great strength is required, and there is also no tend- 
ency to sliding of the voussoirs. 

Fig. 77 shows a semi-oval arch approaching in form 
that of the ellipse, and struck with three centers. 
This form of arch has a somewhat crippled appearance 
at the junction of the small and large curves, and is on 
that account not pleasing to the eye 


1 



It may be here observed that the true ellipse is 
obtained from an oblique section of the cone, and no 
portion of its curve is any part of a circle, and cannot, 
therefore, be drawn by the compasses or from centers. 

The method of setting out and drawing the joints 
requires but little explanation, AB being the span, 
CE the rise, and DD and F the centers, from which 






















ARCHES AND JOINTS 24; 

the curve is struck, the joints converging to their re¬ 
spective centers. 

The left-hand half is shown with square bonding on 
face, and the right-hand half shows line of extrados. 

Fig, 78 is a Tudor arch, based on the curve of the 
hyperbola. 

Let AB be the span and CD the rise of arch; erect 
perpendicular at A , and make it equal in height to 
two-fifths of the rise, as at AC and CD , each into six 
equal parts, and draw lines from 1 to 1, 2 to 2, 3 to 3, 
etc., and the line drawn through the intersections of 



these points gives the curve of one side of the arch. 
The other side is obtained similarly. 

A thin, flexible lath is generally used for guidance in 
drawing an easy curve through the points of inter¬ 
section. 

To draw the arch joints: 

At any point in the curve, say at E , drop a perpen¬ 
dicular on to the springing line, as F , make BG equal 
BF y and from G draw line to A, which is tangent to 
the curve, and erect the perpendicular EH , giving the 
arch joint required. 








248 


STONEMASONS’ GUIDE 


The other joints are described in the same manner. 

Fig. 79 is another example of the Tudor arch and is 
a parabolic curve. 

Let AB be the span and CD the rise, erect a perpen¬ 
dicular at A and make it equal in height to half the 
rise, and proceed as in previous figure. 

To draw the arch joints: 

At any point in the curve, say at E, draw the chord 
line BD , and bisect it in F. Join FG , cutting the 
curve in H , and from the point E draw line £/parallel 
to EF y cutting FG in J\ on the line FG make HK 



equal to HJ, join EK and draw EL perpendicular to 
KEy thus giving the joint line required. 

The other joints are described in a similar manner. 

Fig. 80 shows a straight or flat arch, the joints radi¬ 
ating to a common center. 

On the right-hand half the joints are not continued 
through to soffit or top, but have a small portion 
squared on, thus relieving the acute angles of arch 
blocks, which are otherwise liable to fracture. 

The springer on left hand has additional strength in 
having a square seating on skewback. 

In flat arches a camber of an eighth of an inch in a 








ARCHES AND JOINTS 


249 


foot to soffit is usually given to allow for any depres¬ 
sion or settlement. 

Fig. 81 is another example of the flat arch; the left- 
hand half has rebated or step joints, and the right- 
hand half has joggle joints. All these joints converge 
to a common center. 

Fig. 82. — In 
this figure a lin¬ 
tel with double 
joggle vertical 
joint is given. 

Fig. 83 shows a 
lintel with curved * Fig. 80. 

joggle joints, and 

is an example not often met with. 

The form of joint in Figs. 81, 82 and 83 is a little 
wasteful of material; but where stone is plentiful and 
in small blocks, good lintels may be obtained. Many 
examples of these may be seen in our modern Gothic 
buildings. 

Fig. 84 illustrates a window or door head with quad¬ 
rant corners; the stretching-piece or key is in one 

stone, with arch¬ 
joints resting on 
the skewbacks. 

Fig. 85 is an¬ 
other form of 
head, the square 
Fig. 81. seating in each 

stone giving addi¬ 
tional strength, and the joints converge to common 
centers. 

Fig. 86 shows chree joints used in landings. 

A is a joggle joint, commonly called he and she* 



















250 


STONEMASONS’ GUIDE 


joggle. A tongue is cut slightly tapering on one 
edge, fitting into a corresponding groove worked in 
the other edge. Run in with cement, it forms a strong 
and secure joint. 

B is a rebated joint; this is sometimes undercut. 

£7 is a bird’s-mouth joint. Grooves are roughly cut 
in on the edges of these joints opposite each other, 
and the cavities 
run with cement 
grout. Slate dow¬ 
els are also laid 
longitudinally in 
the joint and run 
with cement. 

Fig 87 is a horizontal lintel or architrave spanning 
an opening, with an apparent vertical joint, but con¬ 
cealing a secret arch joint. This is used chiefly in 
colonnades, porticoes, etc., where stones of a suffi¬ 
cient length are not attainable, and sometimes also for 
convenience of hoisting and fixing. 

An indent is formed the shape of the reverse of a 
wedge in joint of abutment, and a wedge-shaped pro¬ 
jection is cut in key¬ 
stone, fitting neatly 
into the indent. 

This makes a good 
and secure joint 
without doweling or 
cramping. . 

Fig. 88 shows sketch of weather or saddle joint in 
cornice. This joint is made by leaving at each end of 
the stone a ridge or roll, the formation of which is 
generally left till after fixing. This roll effectually 
prevents the water running through the joint. The 






ARCHES AND JOINTS 


25 


roll is not usually seen from the front, as the nose of 
cornice is continued straight through the joint, although 
it is also in some cases made a feature of. 

This joint is used chiefly for cornices and window 
sills where there is a large projection. 

Fig. 89 exhibits 
a rebated joint in 
gable coping. 

This joint is 
serviceable, inas¬ 
much as it keeps 
the water out of 
the joint and the wall dry, although it is somewhat 



expensive. 

Fig. 90 is an example of various bed joints in stone 
spires, being respectively: 

A. A horizontal bed joint. 

B. A bed joint at right angles to batter 

C. A rebated or stepped bed joint. 

D. A joggle or tabled joint. 



Fig. 85. 


The bed joints of the stones are usually cut at right 
angles to the batter or face of the spire, as at B; but 
horizontal beds, as at A, are supposed not to involve 
so much thrust at the base. But for obviating any 






















































252 


STONEMASONS’ GUIDE 


outward tendency, a chain or rod-bond, united at the 
angles and inserted in a cavity at the base of the spire, 
is sometimes used. 

The two bed joints C and D are both a little wasteful 
of material, but for stability and strength these are by 

far the best form 
of joints. 

A word may be 
said as to the 
thickness of the 
work; this will 
depend chiefly on the height of the spire and the 
quality of the stone. From ten or twelve inches at 



the base, diminishing to six inches or even less at the 
top, may be generally considered sufficient. 

The stonework of the spire of Salisbury Cathedral 
(the spire, reckoning from the tower, being 204 feet in 
height) is two feet thick at the base, and gradually 










ARCHES AND JOINTS 


253 


diminishes in thickness to about twenty feet above the 
tower, where it is reduced to nine inches, and is con¬ 
tinued at that thickness to the capstone at the summit. 

Fig. 91 shows ashlar in courses with joggle joints. 

This is a 
very unusual 
form of joint, 
and is used, no 
doubt, more 
for effect than 
utility. There 
is a waste of 
material and 
labor, and a 
better result 
may be obtained by the use of slate cramps. However, 
there are some examples of it in modern buildings. 

Fig. 92 is a seating to sill, with a slate or copper 
dowel to prevent lateral motion. 
Mortises are cut opposite to 
each other in the two beds, 
and the dowel made secure by 
being run in with cement. 

The dowel is a most useful 
adjunct in good and secure 
fixing. 

Fig. 93, A, is a metal cramp 
for securing joints together. 
A chase or groove is cut in the 
stone of a sufficient width and 
depth, and at each end a mor¬ 
tise hole is cut to the exact size of inside of cramp, so 
that it fits tightly and requires to be tapped into its 
place; it is then run with melted brimstone or cement 













254 


STONEMASONS’ GUIDE 


The use of iron cramps and dowels in connection 
with stone is generally attended with some danger, on 
account of the iron rusting, which causes an increase 
in size, and subsequent fractures and discoloration of 
the stone. But if the iron is properly protected by 
galvanizing or japanning, the 
risk is reduced to a minimum. 

The best metals for cramps, 
dowels, etc., are copper, gun 
metal, or brass, but these are 
expensive and are therefore 
not much used. 

B is an example of a slate 
cramp also used for connect¬ 
ing joints together, and is 
an excellent and economical 
substitute for metal. It is 
made dovetail in shape, let 
in flush to the bed of the 
stone, and then run in with 
cement. 

Fig. 94 shows a plugged 
or lead doweled joint. This 
is chiefly used in copings, 
curbs, strings, arches, etc., 
and prevents the joint work¬ 
ing loose or “drawing.” 

Two holes, dovetail in 
shape, are sunk in the joints 
opposite each other and a 
small groove is cut from the top to each hole and run 
in with cement 

Slate dowels are sometimes used for this purpose, 
and run in with cement. 



Fig- 90. 


ARCHES AND JOINTS 255 

Fig. 95 shows a lewis, or holding-down bolt, let in a 
dovetail hole and run in with lead. 

The openings in stone of small span arches are 
generally bridged by stone lintels in one piece, or 
lintels built on an arched construction if a number of 



stones are used. If lintels of one piece are employed 
in walls other than ashlar, a rough arch is generally 
built above to relieve the lintel of the weight of the 
superincumbent wall, as shown in Figs. 96 to 98. A 



second method of relieving the lintel, commonly 
adopted in snecked rubble work, is to construct a flat 
arch of three stones above the lintel, as shown in Figs. 
99 to 101; the center stone or key is termed the save. 
In bedding the save stones no mortar is placed on the 












256 


STONEMASONS’ GUIDE 


lintel, but the stones are supported in their position by 
means of small wood wedges. After a sufficient mass 
of the wall has been built to tail down the side saves, 
the wedges are removed. In finishing the wall, the 
joint between the saves and the lintel is pointed only; 
thus no weight from the wall above is brought to bear 
on the lintel. 

A large number of stone openings are formed with 
flat heads, and where stones of sufficient dimensions 
cannot conveniently be obtained in one piece, some 
form of flat arch is adopted. 



Fig. 95 . 


Fig. 94. 


Figs. 102 to 105 show a flat arch, with secret jog¬ 
gles. These latter are worked out of the solid stone, 
the key having two joggles; the springer is recessed 
only, and is made sufficiently long to tail well into the 
wall, the remaining voussoirs being joggled on one 
bed-joint and recessed on the other; the cornic-e over 
window in this example is supported by a console or 
bracket. 

Figs. 106 to 108 show the construction as a flat arch, 
the bed-joints stepped to prevent any voussoir sliding 
on its bed-joint. This method is largely used for 
terra-cotta work. This example illustrates an archi¬ 
trave about window, supported at sides by a half col¬ 
umn with cushion frieze and segmental pediment 
above. The internal jambs are splayed, and illustrate 



Fig. ioi. Fig. 99. Fig. 97. Fig. 96. 


ARCHES AND JOINTS 


257 





1 



1 - 

1 

J| T 


r A 

! 

<MFt 





/r/ci'jtfon 


m 


.Vi 


\ V 
. \ 



/nbjncJ* 


■ ■» • v ■ 

v • \N 

\ • 

' 

1 

UuTb.inot 




,x\ 

,v\V. 

NS> 



fv 

N'V 

' 

' \\NS' X 1ks > 

"F 


A x 

X 

X 

V 


ZPY: 




-Vj L 


.•C '‘-- 1 -Jj II. **■=-- c'XSareJr-. 




x ,,x\ 

’•■■■ 

^.... 

N^vlc 











„ 



r 

v <. v vC-~ 




F/an 

0**3 + * 


-feet 


Fig. 100 Fig. 98. 



























































































































































































































































































































258 STONEMASONS’ GUIDE 













































































































































ARCHES AND JOINTS 259 
































































































































250 STONEMASONS’ GUIDE 



£'/eio 7 /on 

Check or fieb&Te for c/oor 




F’f&rt. 


. ,/2 . * o 

'Cj/e 


-/ 


H= 


j of feet* 


Figs. log and no. 






























































































































































































































































































Fig. n6. Fig 114. Fig. 113. Fig. in. 


ARCHES AND JOINTS 




26l 




• / 

iv-V 

\yy 

7^> 


T r~ - - 



1 

1 1 ■. .-:_. 





—t— 

/-o 

-k- r-—V 

t 

2. J 


r 

( 





\ 1 






f—-L. 




Fie:, im. Fig. 112. 





































































































































































































































































































262 STONEMASONS’ GUIDE 




Fies. 117 and_n8. 


































































































Fisc. 119. Fig. 120. Figs. 121 and 122. 


ARCHES AND JOINTS 


263 
















































































































































































































































































































264 


STONEMASONS’ GUIDE 


Fig. 123. Fig. 124. 



Fig. 125. Fig. 126. 

the use of sconcheons. A coke breeze lintel case in situ 
is shown over the internal opening. Figs. 109 and no 
illustrate a semicircular opening in an ashlar wall, the 
blocks of which have chamfered joints. In these 
arches it is necessary to extend the bed joints of the 
voussoirs till they intersect the courses of the work; 
this results in the voussoirs gradually getting longer as 
they approach the key. Another method of arranging 
voussoirs is shown on right hand of Fig. 109. In this 
the bed joints of the voussoirs are extended to meet 
the horizontal courses, and are then returned a con¬ 
venient distance along the horizontal course; this 
prevents the vertical joints of the voussoirs coming too 
close together near the springing 














































































ARCHES AND JOINTS 


265 


tigs, in to 113 show a rectangular opening, spanned 
by an arch, the dressings and voussoirs of which 
project beyond the wall face about inches, have 
chamfered joints, and are vermiculated on surface to 
give importance to the opening; this form of opening 
is commonly adopted in the basement stories of clas¬ 
sical buildings. 

Figs. 114 to 116 show a similar opening, the voussoirs 
projecting as they approach the key and the joints of 
the masonry being rebated. This is also used for 
basement stories of classical buildings. 

Stone being a granular material, anything approach¬ 
ing an acute angle is liable to weather badly; therefore 
in any tracery work, having several bars intersecting, 
a stone must be arranged to contain the intersections 
and a short length of each bar, as shown in Fig. 117, 
and the joints should be (a) at right angles to the 
directions of the abutting bars if straight, or (< b ) in the 
direction of a normal to any adjacent curved bar. 
This not only prevents any acute angles occurring, as 
would be the case if the joints were made along the 
line of intersection of the moulding, but also ensures a 
better finish, as the intersection line can be carved 
more neatly with the chisel, and is more lasting than 
would be the case if a mortar joint occurred along the 
above line. In no case, either in tracery, string 
courses, or other moulding, should a joint occur at any 
miter line (Fig. 118)= 

Figs. 119 to 122 illustrate the jointing and building 
up of a pointed arch with plate tracery and a rere-arch. 
Figs. 123 to 126, illustrate a pointed arch in three 
orders, with inner opening raised to allow door to 
open. 

Tracery.— Wherever the moulded members of the 


265 


STONEMASONS’ GUIDE 


tracery admit of it, the practice should be followed of 
designing the tracery and fitting in rebated stone 
reveals, similar to the method of fixing wood frames 
in reveals, as it is found to be easier to fix the tracery 
after the opening is built. 

STONE STAIRS AND STEPS 

These consist of a number of blocks, fixed at regular 
and convenient heights, to facilitate transit between 
planes of different levels, and are of three kinds: (i) 
those stairs supported at both extremities; (2) those 
fixed at one end, (the other end being left free), and 
known as hanging steps; (3) steps circular in plan. 
These latter are divided into two classes: (1) those 
with a central newel; (2) those with an open well. 

The steps may be in one of two forms, either rectan¬ 
gular or spandrel, as shown in Fig. 127. In the com¬ 
moner stairs the rectangular blocks are used, but where 
a good appearance is desired or to gain head-room, 
spandrel steps are employed. The spandrel steps may 
be finished in one of three ways: (1) with a plain soffit, 
which consists in finishing the soffit in one plain sur¬ 
face, as shown in Fig. 127; (2) a broken soffit may be 
employed, as shown in Fig. 127; this is used for one 
of three reasons, or for all combined: (a) to gain 
strength at the back of the tread; ( b ) to save the 
expense incurred in working the surface of each step 
perfectly level; (c) to obtain effect; (3) having the 
soffit moulded. 

Each step may simply rest upon the one below it, 
but it i 3 usual for the upper step to be rebated over 
the back of the one below to prevent sliding. To 
avoid acute angles at this point, and to form an abut- 


STONE STAIRS AND STEPS 


267 


ting surface, particularly in the spandrel steps, a 
chamfer is taken off the top back edge of the lower 
step at right angles to the pitch of the stairs, the upper 
step having a corresponding sinking to fit. This is 
known as a back joint, and is shown in Fig. 127. 

Fixing the Steps. —Stone stairs are erected in one of 
two ways: (1) they may be built in the walls as the 
latter are built, or (2) spaces may be left in the walls 



to receive the ends of the steps, which are fitted and 
fixed when the wall is finished. The wall should be 
built in cement mortar for at least 12 inches above and 
below the line of the stairs, the gaps to receive the 
stairs being temporarily filled up by brickwork bedded 
in sand. 

The ends of the steps should be pinned in the walls 
with tiles or slates set in cement, care being taken that 
the space left about the end of the step is filled up, as 
























































268 


STONEMASONS’ GUIDE 


far as possible, with solid material, leaving no thick 
mortar joints to squeeze out. While the steps are set¬ 
ting, the outer or free end should be supported with 
wood struts, after being leveled, which should remain 
until the cement has thoroughly set. 



The first kind of stair, viz., those supported at both 
ends, combine convenience with the greatest strength. 
They are much used in schools, theaters, and other 
public buildings. They are usually made of rectan¬ 
gular steps, which rest six inches on the wall at either 
extremity. 





















































































STONE STAIRS AND STEPS 


269 


The second kind, or hanging steps, are much superior 
in appearance to those last described. They derive 
their chief support from the walls, but each step 
receives an additional amount from the one directly 
beneath it. These are used for all conditions of stairs, 
from the secondary staircases in dwelling-houses to the 
grand staircases in public buildings. In the com¬ 
moner kinds, rectangular steps are used; but in the 
superior, spandrel steps are always employed. 

The steps maybe plain or have moulded nosings; 
where the latter are employed, the moulding should 
be returned about the free end, the moulding on the 
latter being returned and stopped directly beneath the 
riser of the steps above, as shown in Fig. 127. 

When the staircases are very wide, it is advisable to 
support the steps at their outer ends by steel joists or 
cantilevers at intervals, the strength of stone under 
cross stress not being very great. Fig. 127 shows a 
landing supported by a joist. 

The first of the third class of stair, the circular 
newel, is used for turret steps; they are built in a 
circular chamber. The steps are wedge-shaped, their 
thin end being worked circular to a radius of about 3 
inches, the front edge of each step being tangent to 
this circle, the back edge of the step being a radial 
line. The steps are built into the walls of the cham¬ 
ber, at their wide ends, each of the circular ends being 
arranged to fall directly over the one beneath it, thus 
forming a continuous newel up the center. These form 
a strong stair, but are rather dangerous, as they have 
to be steeply pitched to gain the necessary head-room. 

Secondly, those formed with an open well are built in 
the same manner as the hanging stair, of which they 
form one variety. Stairs, circular and elliptical in 


270 STONEMASONS’ GUIDE 

plan, are often built between two walls, as in the first 
class of stair. 

Large stone landings which cannot be obtained out 
of one piece of stone are joggled at their joints, and 
where the slabs are thin and are likely to be subjected 
to heavy traffic, should be supported by steel girders. 

The balusters in stone staircases are always of iron, 
which is better for fixing purposes. There are two 
methods of fixing balusters: (i) fixing them into the 
top, suitable for standard balusters, as shown in Fig. 
127; (2) fixing them into the side, when they are 
termed bracket balusters, as shown in Fig 127. Holes 
are bored in the steps at the proper intervals, being 
slightly undercut. The ends of the balusters are 
indented before being inserted; they may be fixed in 
with lead, Portland cement, sulphur, and sand, or 
asphalt, as previously described. 

Figs. 127 and 128 show plan, elevation, and details 
for an open well hanging stair, built of good hard stone. 
The lower flight shows handrail supported by standard 
balusters, the upper portion with bracket balusters to 
obtain the maximum quantity of available stair space. 
The method of setting out a scroll and curtail step is 
shown. 

Stone Roof.—Fig. 129 shows the method of forming a 
stone-covered roof over a vaulted chamber, such as was 
frequently used during medieval times in military and 
monumental buildings. It is formed of stone flags 
bedded on rubble filling over the vault. In these roofs 
the flags are laid in two systems, the lower and the 
upper; in the first the flags are spaced apart, in the 
second the flags are bedded with a lap of 2 or 3 inches 
over the top edges of the flags in the first system 
The whole upper surface has a slight fall for drainage 


STONE STAIRS AND STEPS 










272 


STONEMASONS’ GUIDE 


Mouldings.—Mouldings may be classified under two 
heads, Classic and Gothic. The Classic are those 
derived from those employed by the Greeks and the 
Romans Invariably the Roman mouldings are found 
to have their prototype in the Grecian examples, the 
chief difference being that the Greek are either seg- 
ments of some of the conic curves or are struck free¬ 
hand, while the Roman curves are all segments of 
circles (Figs. 130 to 138). 

There are nine typical examples, as follows: 

1. Fillet .—This is a narrow, flat projection, often 
used to divide individual mouldings or groups of 
mouldings in any composition; it is similar in both 
Greek and Roman work, as shown in Fig. 134. 

2. Astragali s a small semicircular moulding, as shown, 
often used in combinations of mouldings, but chiefly to 
mark the division between the shafts and caps of col¬ 
umns. This member is similar in Greek and Roman. 

j. Cavetto .—The cavetto is a hollow moulding, con¬ 
sisting in the Greek of a quarter of an ellipse and in 
the Roman of a quadrant. 

4. Ovolo .—This moulding in the Greek consists of a 
segment of an inclined ellipse, having’ a fillet at the 
top and bottom, and forming at the top a quirk. In 
Roman work it is a quarter circle, bounded at top and 
bottom by a fillet. 

5. Cyma Recta .—This is a double curve, formed in 
the Greek of two quarter ellipses whose minor axes are 
in the same straight line and bounded top and bottom 
by a fillet. The Roman example is similar, but consist¬ 
ing of two quarter circles. This moulding has a con¬ 
cave portion of its surface above the convex, and is 
generally used as a crowning member. 

6 . Cyma Reversa, as its name implies, is the reverse of 


STONE STAIRS AND STEPS 


n. 


Crown mg 
Mould ing's 


Cyma 
o Recta 


Cavetto 


Su/i/iorfing 

Mouldi ngs 



Connect in 
Moulding* 


Fillet 
n Bando) 


Astragal 


Base 
AiJou/dmgs 



Scot/a 


Torus 


Birds Besik. 

Figs. 130 to 138. 


the preceding moulding, 
slightly modified in the 
Greek by having a quirk 
above, between the same 
and the fillet, and the hol¬ 
low portion slightly more 
concave. The Roman is 
an exact reverse. 

7. Scotia .—The scotia in 
the case of the Greek is 
formed of an inclined 
ellipse, having a fillet 
above and below. The 
Roman is struck from 
two centers on a common 
radial line. 

L/stel 8. Torus .—The torus is a 
base moulding, the Greek 
form being the reverse of 
the scotia. Many Greek 
examples are, however, 
similar to the Roman, 
consisting simply of a 
large semicircle with a 
quirk below and fillet 
above. 

q. Bird's Beak. — This 
moulding only occurs in 
the Greek mouldings; it 
consists of a quarter 
ellipse, with the major 
axis horizontal, in the 
lower side of which 
a small hollow has 





274 STONEMASONS’ GUIDE 




Types of Gothic Mouldings, 
^igs. 139 to 







STONE STAIRS AND STEPS 


275 

been worked, and is used as a supporting moulding. 

In the designing of groups of mouldings for cornices, 
strings, etc., reference should be made to the suit¬ 
ability of the forms for their intended position, and for 
this purpose they may be divided into base mould¬ 
ings, connecting mouldings, supporting mouldings, 
and crowning mouldings. The base mouldings would 
include such mouldings as the torus, the scotia or the 
inverted cyma recta, and any combination of such 
mouldings that would tend to broaden the base and 
distribute the weight of the mass supported. 

Connecting .—These include the fillet and the astragal. 

Supporting .—The supporting mouldings include such 
members as the ovolo, bird’s beak and the cyma reversa, 
mouldings that do not have their hollow members near 
their upper edge, and such as have their mass in a posi¬ 
tion to strengthen them, and are fitted to act as cor¬ 
bels. These mouldings are used to form the bed 
mouldings or lower parts of combinations, such as 
cornices which are divided into two parts, the bed 
mouldings and the crowning mouldings. 

Crowmng Mouldings are those mouldings which are 
not expected to carry anything above, such as the cyma 
recta and the cavetto, the top members of which are 
small and delicate. 

The above ideas are not always rigidly adhered to, 
and successful departure from them is often made with 
good effect; but it is prudent to bear these principles 
in mind when designing any groups, ’for if too widely 
departed from, confusion ensues. 

Gothic Mouldings. —Figs. 139 to 165 give a selection 
of the mouldings commonly used in the Gothic 
periods, combinations in archivolts, also for strings, 
wall bases, bases and capitals of columns. 


SPECIFICATION CLAUSES 


MATERIALS 

STONE 

1 . The whole of the stone to be of the best description of its 
respective kind, and to be free from sand holes, vents, flaws, and 
all other defects. Should it be disapproved it shall be removed 
at once from the site. 

2 . Any stone which will not sustain a load under test of 2 -in. 

cubes equal to.lb. per sq. in. may be rejected and the 

contractor is to furnish to the architect, if demanded, fair cut 
cubes taken from any stone challenged by the architect, and the 
test of such cubes shall be considered a test for all the stone of 
a similar character. 

3 - The.stone is to be obtained frorti the 

quarry of. .. to be equal in all respects to 

sample blocks deposited with the architect, and approved by him 
in writing. 

Note.— This clause should be repeated for each different stone 
to be employed in the building, to prevent the substitution of an 
inferior material. In no case should an architect specify partic¬ 
ular stone by a general trade name. In the case of sandstone 
for sills, hearths, etc., the following clause may be used. 

4 . The stone is to be of an approved quarry, and the contractor 
is to deposit samples of the stone he proposes using with the 
architect, and obtain his approval in writing before ordering same. 

5 . All cut stone work of every description, including window 
and door sills, caps, corbels, cornices, steps, railings, brackets, 
balcony floors, chimney caps, copings, fireplace lintels to be cut as 
per plans, details, etc., for the same, and to be delivered at the 
building properly fitted and with all necessary lewising and drill¬ 
ing for anchors by the stonecutter. 

6 . Any stone found at completion to be broken or defective is 
to be cut out and replaced by the contractor. 

276 





SPECIFICATION CLAUSES 


277 


MATERIALS FOR OTHER TRADES 

FOR “DRAINLAYER” (HOUSE DRAINAGE) 

7. Provide good stone covers for air inlet chambers, 2 ft. 9 in. 
by 2 ft. 9 in. by 4 in. thick, finely tooled on top and edges, with 
rebated perforation for cast-iron hinged grating in frame. 

8. Provide good stone covers 3 ft. by 3 ft. by 4 in. thick, for 
partially covering manholes, as shown on drawings, with circular 
perforation, 1 ft. 9 in. in diameter, for entrance. 

9. Provide stone covers, 2 ft. by 2 ft. by 4 in. thick, for tops 
of lamphole shaft, terminating in roads or carriageways, with per¬ 
foration the full diameter of the top of the pipe. The covers to 
be finely tooled on the top and edges, and to have 3 in. block 
letters “L. H.” cut in on the surface. 

10. Provide for inspection junctions stone covers, 18 in. by 
18 in. by 3 in. thick, finely tooled on top and four edges to have 
3-in. block letters “I. J.” cut in on the surface. 

11. Provide for the cleaning eyes stone covers, 18 in. by 18 in. 
by 3 in. thick, finely tooled on the top and four edges, to have 
3-in. block letters “C. E.” cut in on the surface. 

FOR “MECHANICAL ENGINEER” 

12. The cover for engine bed to be of.stone, 16 in. 

thick, with chamfered edges, holed through in four places for hold¬ 
ing down bolts, all as shown on drawings. 

13. The coping for walls of flywheel race to be 9 in. by 6 in. 
.stone boasted coping. 

14. The flag cover for boiler sides and flues to be 3-in. hard 
.stone flags with boasted overhanging edge. 

15. The coping for blow-off pit to be 9 in. by 6 in. 

stone boasted coping rebated for iron plates. 

WORKMANSHIP—GENERAL WORK 

16. All stone work to be set in best manner, every stone well 
bedded with complete full squeezed out joints in cement mortar, 
and all work in contact with brick to be plastered with similar 
cement to protect from stains, and all the brick backing of same 
to be set in similar cement mortar. 

17. All stones to be well wetted before setting, and large stones 
to be set with a derrick Rake out mortar joints when setting. 






STONEMASONS GUIDE 


18. The joints between cut stone blocks in all columns or where- 
ever any weight is brought on any cut stone work to be made 
with 5-lb. sheet lead worked back from the face 2 in., the center 
being cut out to allow space for settlement. 

19. No angle miters will be allowed in any part of the work. 

20. All window sills and all belts forming window sills to be in 
one stone each if desired by the architect. 

21. The lines of all mouldings, curves, angles or miters to be 
worked to their true and proper forms, and all returns of miters 
of mouldings, washes or bevels to be worked on and out of the 
solid. The beds and joints of all stonework to be square with 
the face. 

22. All rebates for frames to be cut in the stone joints accord- 
ing to plans and directions of the architects. All the windows 
or other finish of stone to be in size and form as shown on detail 
drawings, moulded, etc., according to the details of each part. 

23. All stonework to be jointed as shown or directed. 

24. Fix in all joints, where shown on details or as directed, 
copper dowels (provided by “coppersmith”), tailing equally into 
each stone, and run with oil cement. No iron dowels, galvanized 
or otherwise, will be allowed, and if brought on the job shall be 
returned immediately. 

25. Carefully perform all cuttings and dowelings of holes for 
iron railings, crestings, bars, anchors, etc. Also all cutting for all 
galvanized iron, tin and lead flashing to the several roofs and 
wherever else required. 

26. Chases to be left in all walls where shown on drawings, or 
wherever required for the running of steam, gas, and water pipes, 
or for any other purposes which may be found to be necessary 
after the work has been built. 

Cut chases and break out holes for steam, water and gas pipes, 
or for any other purpose. 

27. The front entrance to have ..in. by ..in.stone 

rubbed top and front, and back-jointed step with sunk and 
moulded front, and with short returned sunk and moulded 
ends. 

The tradesmen’s entrance to have ..in. by . in. good free 
stone, tooled top and front, and back-jointed step. 

All steps to be kept up 2 in. above floor to allow for thickness 
of mat. 

The doorways to 


to have. . in. sound, free stone, 




SPECIFICATION CLAUSES 


279 

Tubbed, and back-jointed both edges, thresholds the full widths 
of the walls. 

All steps and thresholds to have mortises for dowels of door 
frames. 

28. To be of.stone 14 in. by 6 in., wrought, sunk, 

weathered, throated, and rubbed on all exposed parts, including 
the soffit of the projection, grooved for metal tongues, and set in 
mortar. 

All to have proper stools for jambs. 

29. Finish the parapet next.with 14 in. by 6 in. 

suitable stone rubbed saddle-backed, double-moulded (to detail), 
and double-throated coping, with kneelers, springers, bonders^ 
etc., of the sizes shown. 

Finish the parapet over.with 13 in. by 3 in. suit¬ 

able stone, tooled and weathered coping throated on both edges. 

All copings to have lead-plugged joints. 

Note. —Iron should not in any case be used as cramps. Should 
cramps be preferred to lead plugs, copper or gun metal should be 
used. 

30. Carefully bed and dowel all cornices in cement mortar. 

31. The heads to windows where shown to be stone to be of 

.stone stop, moulded to detail of the sizes shown, 

and 6 in. longer each end than the width of the opening. 

32. The staircase from ground floor to basement to have. .in. 
by . . in. tooled all round threads, and .. in. by .. in. tooled all 
round risers. 

The staircase from ground floor to.to have . .in. by 

..in. rubbed all round.stone spandril steps, splay 

rebated and splay back jointed with sunk and moulded fronts 
with solid square wall ends. The other ends to be returned and 
moulded to match fronts. 

The bottom step to be solid with curtailed end as of the size 
shown. 

The landings to be. . in. thick, sunk and moulded on free edges 
to match steps with cement-plugged joints. Fill in between 
landing and steps below same with . . in. by . . in. splay rebate 
and splay back-jointed filling-in piece with fine rubbed joint. 

All ends of steps and edges of landings next walls to be built 
in at least 4^ in. 

33. Properly cut and pin, or build in the walls, all ends of steps, 
edges of landings, etc., requiring it. 








280 


STONEMASONS’ GUIDE 


34. Put 4 in. rough.stone corbels under all over¬ 

hanging chimney breasts. 

35. Turn relieving arches of such span as may be directed in 
walls over weak spots in the foundations or over openings. 

36. Put under ends of rolled joists up to . .in. by . .in., 14 in. 
by 9 in. by 3 in., under ends of larger rolled joists 14 in. by 14 in. 
by 4 in., and under ends of riveted girders 18 in. by 14 in. by 6 in. 

.stone templates, finely tooled for iron, and with 

tooled edges where exposed. 

37. The columns and stanchions to have 21 in. by 21 in. by 6 in. 

..stone bases finely tooled for iron and mortised for 

lugs. 

Note. —The columns and stanchions to be slightly wedged up 
with steel wedges, and run in with neat -cement. 

38. Chimney stacks to be worked according to detail drawings 
and properly cramped as directed. The top stone of chimneys 
where possible to be in one stone with holes cut through for 
flues. 

39. All rolled joists and girders carrying walls to have 3 in. 
stone tooled covers with coped edges bedded in cement. 

All riveted girders to have bed of cement on top of same to 
cover rivet heads. 

40. Put 3 in. rough stone flags bedded and jointed in cement 
as cover to dry area. 

41. The curb to area outside.to be 9 in. by 6 in. 

.stone tooled all round with cement-plugged joints. 

The curb to area outside.to be similar, but rebated 

for pavement lights. 

42. The kitchen and scullery fireplaces to have 2£-in. stone 
rubbed front and back hearths. 

The remaining fireplaces where stone hearths are shown to 
have 2 in....stone rubbed front and back hearths. 

All to be 12 in. longer than the width of opening and 18 in. 
projection, except to kitchen, which is to be 24 in. projection. 

43. The kitchen chimneypiece to have 1 \ in by 2 in. 


stone rubbed jambs, and 9 in. by 2 in.stone mantel 

and shelf. The shelf to project 6 in...each end beyond 


mantel, with rounded corners, and to be supported on 12 in. by 
6 in. by 2 in. rubbed and moulded stone corbels cut and pinned 
in wall. 

14. Provide and fix.. .stonerubbed and dished sink in 













SPECIFICATION CLAUSES 


281 


scullery 3 ft. by 1 ft. 8 in. by 5 in., all in clear, the bottom to fall 
and holed for grating. 

Note. —Glazed stoneware sinks are generally preferable to 
stone, except in special cases. 

45. Provide and fix as shown a 4 in. chamfered and holed top 

to copper, to be in one slab of rubbed.stone. 

46. Cut all grooves and rebates as may be required for glazing, 
etc., up the jambs and mullions, and in the tracery, and well 
point upon both sides with coarse putty. 

47. Form rebates for iron casement frames, and provide plugs 
and holes in stone to each. 

48. Mortise steps, sills, etc., for tenons of door frame shoes, 
and run in the tenons with lead. 

49. Each bell pull at entrances to be let into a stone 9 in. by 9 in. 
by 9 in., set in cement and sand, sunk for pull, and mortised for 
wire. 

50. Cut proper mortises in the stone for the ends of all saddle 
bars, stanchions, etc., and run in with cement; properly let in 
and run with lead all double fangs of hinges, staples, catches, 
sockets, etc., as may be required. 

51. All works intended for carving to be prepared by the mason, 
and all boasting necessary to be done by him, great care being 
taken to leave sufficient stuff to give the carver plenty of scope. 
The carving to be done by professional carvers approved of by 
the architects, and according to detail drawings to be furnished. 
Carving to be done either on the ground or in position after the 
building is up, as directed by the architects. 

52. Provide and allow for selecting a specially jointed founda¬ 
tion stone and for cutting inscription on same of about. 

letters 2 in. high, and cutting a cavity in same, and provide an 
air-tight solid copper box to hold papers, etc., to be deposited in 
same, and allow for extra labor and materials in setting stone 
with usual ceremonies. Also provide and allow for clearing up 
the parts of the building near the stone on the day appointed by 
the building owner, and making the premises clear and safe and 
available for the usual assembly and allow for interruption of 
such work as necessary. 

53. Thoroughly clean down all work at completion and clean 
out and point all joints in cement, tinted to match stone, well 
tucked into joints and finish with a neat flat surface. 

54. Lime whiten all exterior wall surfaces, mouldings, etc. 




282 


STONEMASONS’ GUIDE 

SPECIAL CLAUSES FOR A CHURCH 


LABORERS 

55. The whole of the stone to be of the best description of its 
respective kind, to the architect’s approval; to be free from sand 
holes, vents and all other defects; to be worked to lie on its 
natural bed when set, and to be bedded and jointed, except 
where otherwise described, in mortar (or putty), with wide (or 
fine) joints, which are intended to show. 

All the stone is to be worked on the site, and particular care is 
to be taken to preserve all the joints of the stonework from the 
irregular appearance which is caused by the arrises being broken 
before the stones are set. No work thus injured will be allowed to 
be used, and no patching will be allowed. The stonework to be 
so truly worked as not to require any cleaning off beyond washing. 

56. All the dressings (unless otherwise described) to be finished 
off with a fine drag (or a chiselled face or rubbed) in a manner to 
be approved by the architect, and to be bonded and fixed in the 
most substantial manner. 

57. The vertical joints of sills, parapets, cornices, and all joints 
in tracery of windows, in vaulting ribs and chimney caps, are to 
have double cement plugs and mortises for same, or double V- 
grooved joints run with cement as may be necessary. 

58. The mullions, copings, jamb shafts, pinnacles, and such 
are to have 1 in. or 1^ in cube slate dowels (as required) to every 
stone in the bed, run with cement, with proper mortises for the 
same 


DRESSINGS 

59. The external dressings of windows and doorways, also the 
copings, strings, 2 ;able crosses, weather courses, weatherings, etc., 

etc., are to be executed in. All external angles of 

dressed stonework to be worked in the solid. 

60. Provide and fix hinge and lock stones as shown on the 
drawings and as required. (It is sometimes advisable to make 
these stones of a harder material than the dressings.) 

61. The internal dressings, unless otherwise described, are to be 

of., finished with finely-rubbed faces. 

62. All internal angles of dressed stonework to be worked in 
the solid. 

63. The detached piers and springers over same are to be exe- 




SPECIFICATION CLAUSES 


283 


cuted in.stone. Internal detached shafts to be of 

.stone (or marble, etc., etc.) as required, the 

whole to have circular, finely-dragged faces, or to be chiseled (or 
rubbed), the top and bottom beds to have mortises run with 
cement, and the intermediate joints to have light copper cramps 
as may be directed. 

ASHLAR 

64. The internal facing throughout to be of.stone ash¬ 
lar. The external facing is to be of.stone ashlar. The 

courses are to be of various heights (averaging 6 in. on the bed) 
from 4 in. to 10 in., and to line generally with the beds of dressed 
stonework. They must also be properly bedded and bonded into 
the body of the walls. Each stone must be set in mortar, cut, 
and properly fitted up to the dressings, arches, etc., and be fin¬ 
ished with a finely-dragged or chiseled face. 

VAULTING 

65. The springers of the vaulting must be worked on the solid 
as shown on detail drawings; they and the wall ribs are to be built 
into the walls as the work proceeds, but those portions of the 
groin ribs which are fully developed on the springers, as well as 
all the filling in, will have to be set after the roof is up and covered 
in. The contractor is to allow for any extra scaffolding, labor, 
etc., that may consequently be required. 

66. The cells of vaulting are to be filled in with.stone 

4 in. thick in narrow courses built in mortar, the soffits to be 
slightly arched or cambered, and the surface to be finely dragged 
or chiseled to match the internal ashlaring, etc.; it is to be 
cleaned off and the joints struck as the work proceeds, to be pro¬ 
perly cut up to the stone ribs, and to have all necessary centering 
or laths that may be required for the support of the cells whilst 
building. 

SUNDRIES 

67. The gable crosses to be of.stone worked according to 

the drawings, and fixed with 3 in. by 1 in. by 1 in. slate dowels 
run with cement. 

68. The masonry in all towers to be built with special care with 
large flat stones, carefully bedded, each stone to break joint over 

the center of the stone below. Not more than..stones to 

be placed in the width of the wall set in mortar and grouted as 
described for the other portions of the work. All joints to be 









284 


STONEMASONS’ GUIDE 


true and close, filling in the walls with spalls will not be allowed. 

69. The tops of the turret and chimney stack are to be built 
as shown on the drawings, the top and cap stones of turrets and 
the top stone of chimney to be solid and perforated for the flues 
and finial rods as required. 

70. A weather course to be fixed round chimney stack, also on 

., all with solid springers, apex, and bond stones 

about 4 ft. -apart. (Some prefer to work these entirely on the 
solid.) 

71. The chimney-piece in vestry to be formed in. 

stone, as shown by the detail drawing, and to be properly dow¬ 
eled together and tied with copper cramps into the walls. The 
fender to be of stone, by in., rubbed and moulded, with 
dowels and cement plugs as required, and to have circular comers 
as shown by the drawings. 

72. The Seats in sedilia, the bottom of piscina, etc., to be also 

of.stone, all of the widths and thicknesses shown. 

FLOORS AND STEPS 

73. The altar stone to be a 6 in. rubbed.slab in one 

stone, and of the size of the altar as shown. 

74. The steps within the chancel and at the entrances thereto 

are to be of the best selected.stone, rubbed top and 

front and back-jointed; to be in long lengths with fine joints and 
double cement plugs in same, and of the sizes shown; all to be 
bedded hollow on brickwork. Similar steps to be fixed. 

75. The heating vault and.to have 2 \ in. tooled. 

paving in mortar. 

CARVING 

76. Provide models to the approbation of the architect, made 
by an artist, for the whole of the carving; the whole to be made 
to a-scale of 3 in. to 1 ft. 

77. Perform in an artistic manner to the satisfaction of the 
architect, the carving of the pendants, battlements, foliated 
arches, finials, crests, small domes, and of every other part of 
the building. 

Note.— It is more often the custom in the best work to insert 
a provision for the carving of a building, such sum to include cost 
of making necessary models. 

78. Clean down the masonry work and generally leave the 










SPECIFICATION CLAUSES 


25 $ 


Whole perfect and complete, omitting no material or workman- 
ship either described or implied by the drawings and this specifi¬ 
cation, or that is necessary to render the whole complete in every 
respect. 

Note. —Many architects will not allow any cleaning down. 
There is little doubt but that the custom is injurious to some 
stones, as it removes the natural case-hardened weather-face. 

SPECIAL CLAUSES FOR A BUILDING IN A STONE DIS¬ 
TRICT 

79. The stone for wallings, footings/ and dressings generally 

to be obtained from.quarry. (If the quarry belongs 

to the building owner, insert the following:—No royalty will be 
charged, but the contractor will have to quarry the stone and 
convey it to the building. The quarry to be left in good order at 
completion.) Stone for sills, mullions, transoms, string courses, 
cornices, copings, weatherings, and other exposed positions to be 

obtained from the.quarry belonging to Mr. 

The whole of the stone to be set so as to lie on its natural quarry 
bed. 

80. Build the footings with large flat-bedded rubble walling 
stones, specially selected for the purpose, in mortar thoroughly 
bonded, bedded perfectly level, filled in solidly, and flushed up 
with mortar. 

Properly lay lip the cellar walls with good hard flat build¬ 
ing stone.in. thick, firm built and well bonded with a 

thorough stone at least in every yard super., laid in clean lime 
and cement mortar in parts of one of cement and two of lime, 
laid by and full to a line on both faces and flush and point at 
completion. Lay down in like manner substantial foundations 
under all chimneys, piers, and exterior steps, and all clear, of 
frost. Leave all openings in walls for drain, gas and water pipes, 
as directed or as shown on plans. 

81. The walls to be carried up in roughly-chiseled ashlar in 
mortar, to be thoroughly bonded and packed, and well flushed up 
with mortar and small stones. 

82. The inside face to be carried up true and even in brick¬ 
work to receive plaster (4£ in. lining properly bonded with head¬ 
ers into wall). 

83. The outside surface to be executed in roughly-chiseled 






286 


STONEMASONS’ GUIDE 


ashlar (the local rubble stone in horizontal random courses to 
average 7 in. on bed with one bond stone at least to every yd. 
super., the beds to be roughly hammer dressed, and the surface 
to be chopped to remove any great irregularity as shall be directed, 
the courses to vary from (3 in.) to (7 in.) high, and in stones 
between (14 in.) and (24 in.) long with occasional large square 
stone). The pointing to be done as the work is carried up by 
passing the point of the trowel over the joint, so that the mortar 
shall in no case project over any portion of the stones, and the 
joints to be slightly weathered. 

84. The quoins to be got out of the best local weather stone, 
to be long each way on the bed, and well bonded into rubble 
walling, the angles to be truly formed, and the surface to be axed 
with irregular upright and diagonal strokes as shall be approved, 
or, if of rubble, “the quoins to be executed in selected large stones.” 

85. Provide for covering the tops of walls with asphalted felt 
if they should be uncovered during frost or very wet weather. 


APPENDIX 


In order to make this book as useful as possible I have thought 
it proper to add this Appendix to it, which, in my opinion, offers 
the best and most simple solutions to the problems discussed 
in this department. It is taken from the works of Wm. R. 
Purchase, one of the best known authorities on Cut Stone Ma¬ 
sonry. The subjects dealt with are of the most difficult kind 
known to the art of masonry, but here they are reduced to 
the simplest manner possible, and the rules are made so plain 
that any ordinary workman should be able to thoroughly under¬ 
stand them. 


ARCHES 

CIRCULAR ON PLAN, OR ARCHES OF DOUBLE 
CURVATURE 

To describe the construction of a Semi-circular Arch in a 
Cylindrical Wall, the development of which on convex or 
outside face is a semi-circle, and on concave or inside face is a 
semi-ellipse, the soffit radiating to a center at springing, and 
the crown of the arch level or at right angles to the vertical face 
of the wall. 

Fig. 1.—Shows plan of the arch, BCD being the opening, 
the arch radiating to O, the center of the cylinder. 

To set up the Elevation on the Development for the Face Moulds. 

Fig. 2. —Develop the segment A B C of convex face (Fig. 1), 
setting out the length on springing line as A B C from C as the 
center; erect a perpendicular as center line, and describe with 
C B as radius half of the semi-circle. Set off the joints radiating 
to the center C corresponding to the number of arch joints re¬ 
quired, which in this example is seven. The square bonding 
da, fb,g c of vertical and horizontal joints may be of varied 
sizes. The radiating joints (here shown) are made equal in 
length from the soffit, and for this purpose from the center 0 
describe a quadrant, cutting the joints at ah c. 

287 


288 


APPENDIX 


To find the Development of Concave Face. 

Fig. 3.—Divide the quadrant B K (Fig. 2) into any numbei 
of equal parts—in this example seven—and draw the ordinates 
1, 2, 3, 4, 5, 6, projecting the same on to the springing line, and 
transfer these to the segment line B C on plan (Fig. 1) as 1, 2, 

_ DEVELOPMENTS __ 



3, 4, 5, 6, and from these points draw radiating lines from the 
center 0, cutting the segment B' C' at 1', 2', 3', 4', 5', 6'; draw 
the developed length of B' C' on springing line (which is also 
equal to C' D' and is half of the inside face) from C to D'; transfer 






























APFENDIX 


289 


V, 2', 3', 4', 5', 6' from Fig. 1, and draw the ordinates of equal 
height to those of Fig. 2, cutting Ffg. 3 at l a , 2 a , 3°, 4 a , etc., through 
the points l a , 2 a , 3 a , 4 a , etc.; draw the half of semi-ellipse, which 
gives the curve of the arris to the soffit. 

The length of the joints in Fig. 3 is determined in the same 
manner as in Fig. 2—namely, by means of ordinates. One joint 
is here given as an example: 

From A No. 2 A (Fig. 2) drop a perpendicular cutting the 
springing line at 2 C; and from 2 C to 2 transfer to 2 C and 2 
on the segment line of plan (Fig. 1), and draw radiating lines 
from 2 C to the center 0, cutting the segment A' C' at 2 d; trans¬ 
fer the distance from 2 d to 2' on to the springing line (Fig. 3). 
Set up ordinate and make equal in height to a on Fig. 2, and 
from 2 A to A' (Fig. 3) draw joint line, which also radiates from 
the center C. 

The moulds required for working each arch 
block are a bed mould and two face moulds 
(one to the convex and one to the concave face); 
these are already set out on plan and in developed 
elevations, but now require separating. 

As an example, No. 1 A (Fig. 2) is the springer. 

For the bed mould take A B 2 and A' B' 2' from 
plan (Fig. 1), and transfer to 1 C (Fig. 4). 

The dotted line B B' shows the line of the soffit 
on the bottom bed, the line a a' the line of the 
arch joint on the top bed, A A' the line of radiat¬ 
ing vertical joint, and 2 2' the line of arris of 
the arch joint. This gives the plan of a segment 
of a hollow cylinder to the extreme size of the 
stone. 

No. 1 A (Fig. 4) is the face mould for convex 
face, No. 1 B (Fig. 4) is the face mould for con¬ 
cave face, and both of these are transferred from 1 A and 1 B 
(Figs. 2 and 3), with the addition of the square line 2 2 and 2' 2'. 

The stone for the arch block should be large enough to work 
the bed mould square through; if there is a “wanty” comer in 
the rough block, this may be arranged for in the comer where 
the stone has to be cut away for the soffit or the top joint. 

"Work the two beds bottom and top parallel to each other 
and of the height of the face mou’d, scribe in the bed mould 
No. 1 C on both beds (to be correct this should be boned in), 



Fig. 4. 










290 


APPENDIX 


the vertical joint A d being at right angles to the bed. Next 
work the convex and concave faces through, and also the ra¬ 
diating joint A A', the block at this stage being a portion of a 
follow cylinder similar to sketch (Fig. 7). 

Now scribe in the face moulds 1 A on the convex and 1 B on 
the concave faces (Fig. 4); next work the arch joint a e through 
(this will have a slight twist); and lastly, for the soffit cut in a 
draft Be on convex and B' e' on concave faces, and work the 
surface through, thus completing the springer. 

It may be observed that the soffit is a winding or warped sur¬ 
face, and it will be worked similar to the soffit of winder step, 
as previously described. 

To work the Second Arch Stone, No. 2 A (Fig. 2). 

For the bed mould 2 C (Fig. 

5), project the extreme points 
a and 4, No. 2 A (Fig. 2) on to 
springing line; transfer these 
to the segment line A C on 
the plan (Fig. 1). This gives 
from 2 C to 4 and 2 d to 4', 
which encloses the bed mould; 
a a' is the vertical joint and 
arris of the arch joint a 2, the 
dotted line 2 a is the horizontal 




L 


• <>D MOULI 

;3 C 1 


7 - * 

* line of the joint on soffit at 

1 \ 

FAC ft If 01.0 \ 

bottom, and the line 6 6' is the 

2^ \ 

arris at the top of arch joint, 

• / 

® | / 

4 4 a is the bottom arris of the 

V. 1 / 

top joint to soffit. 


c No. 2 A (Fig. 5) is the face 



Fig, 5. 


Fig. 6. 


mould for the convex face, 
and No. 2 B (Fig. 5) is the 

face mould for the concave face; both of these are transferred 
from 2 A and 2B (Figs. 2 and 3), with the addition of the 
square line 4 b, 4 C, and 4 1, 4 2. 

Work the top bed first / b, 4 6, and take the bottom bed a 2, 
4 C parallel to the top and of the height of the face mould (this 
is a surface of operation, all being cut away except arris 2 2 a, 
which must be kept true across the bed). Scribe the bed mould 
No. 2 C (Fig. 5) on both beds. Now work the two faces convex 
and concave through, and the radiating joint a a' square with 













APPENDIX 


291 


the top bed, bringing it again into the shape of a portion of 
hollow cylinder, as in sketch (Fig. 7). 

Scribe the face mould 2 A on the convex and 2 B (Fig. 5) on 
concave faces. Work the arch joints a 2 and b 4, and for the 
soffit cut in the draft 2 4 on the convex and 2 a, 4 a on concave 
faces, and work through as previously described. 

The other arch stone 3 A and keystone are worked in a similar 
manner, the general principles of working being the same. 

Note. —The radiating joint lines on the developments (Figs. 2 
and 3), to be geometrically correct, should not be straight, being 
slightly curved. This is apparent on cutting a cylinder by a 
right line obliquely, the development of which is a compound 
curve; but in this case the curve is so slight as to be scarcely 
perceptible, and need not in the present and the following ex¬ 
ample be taken notice of. 


Fig. 7. Fig. 8. 

To construct a Semi-circular Arch in a Cylindrical Wall, 
whose line of soffit on the plan is parallel to the axis, the axes 
of the two cylinders intersecting each other at right angles. 

Fig. 9.—Shows the plan of the arch, BCD being the opening. 

Figs. 10 and 11 are the developed elevations. 

In order to prevent confusion with Figs. 9, 10, and 11, and 
to make matters easier of explanation, three diagrams are here 
shown, containing Fig. 15, Figs. 16, 17, and Figs. 18, 19, these 
being slightly exaggerated to show more clearly the working. 

Let Fig. 15 be the plan of segment of cylinder, with the semi¬ 
cylinder penetrating the same at right angles to the axis at 
a e, b d. 

Let Fig. 16 be the square section of the quadrant of cylinder, 
and divide this into any unequal number of equal parts corre¬ 
sponding to the number of arch stones required in Figs. 10 and 
11, which in this example is seven, as 1, 2, 3, 4, 5, 6, 7, and pro- 
















292 


APPENDIX 


ARCHES CIRCULAR ON PLAN 


_ DEVELOPMENTS _ 

HA z_ p CONVEX j . _ HA L.F CONCAVE 9 

( OC/TS/Oe ) j ( / NS/OS ) 



ject on to the segment line a cb on plan (Fig. 15), as C 6, 5, 4, 
3, 2, 1; transfer this to the springing line a b, 1, 2, 3, 4, 5, 6,-7 
(Fig. 17), which is now the developed line; erect ordinates, and 
make them equal in height to the ordinates of the square section, 
as 1', 2', 3', 4', etc.; draw line through the intersecting points 
1 / , 2', S', 4', etc., giving the curve required on the development 
at the point of penetration for the outside or convex face o£ 
cylinder. 





































APPENDIX 


293 


For the development of the inside or concave face, let Fig. 18 
be the square section, divided into seven equal parts, projecting 
the ordinates as before. Transfer from Fig. 15 l a , 2 a , 3°, 4 a , 5°, 
6 a , 7 a to the springing line (Fig. 19), erect ordinates and make 
them equal in height to those of square section at 1, 2, 3, 4, etc. 
and through the intersecting points l a , 2 a , 3 a , 4 a , etc., draw the 
line giving curve required at the point of penetration for the 
inside or concave face of cylinder. 

For the joints draw radiating lines at 2, 4, 6 (Figs. 16 and 18), 
and to make them of equal length draw a quadrant line with 
radius of the square section as fgh, project fgh on to plan 
(Fig. 15) as J g h, and transfer to the springing line (Figs. 17 anc 



Fig. 12. 


Fig. 13 . 


19); erect ordinates at fgh, making equal in height to those of 
the square section. Next draw the joint lines h 2', g 4', / c' on 
Fig. 17, and h 2 a , g 4 a , and f d (Fig. 19); the developed length 
of joint is thus obtained. 

To set up the Elevation on the Developments for the Face Moulds. 

Figs 10 and 11.—Let A E' be the springing line, CK the 
center line, and LKM dotted line the square section of the 
cylinder whose center is C. For the development B K D proceed 
as previously described, and divide into any number of equal 
parts for the arch stones required—which in this example is 
Beven—and draw the joints; the square holding ab, b f. fl may 











294 


APPENDIX 


be set out at will, but should be set out from the inside or con¬ 
cave face, so as to obtain a parallel arch joint. 

The joint c b' t No. 2 C (Fig. 13), which is the arch joint cut¬ 
ting out to the vertical joint b' } illustrates this. 

The moulds for working each arch block are a bed mould and 
two face moulds. These are already set out on plan (Fig. 9) 
and elevations (Figs. 10 and 11), except the addition of a square 
line to the extreme size. 

To work the springer: 

For the bed mould take A c, B d from the plan (Fig. 9) and 
transfer to 1 C (Fig. 12); the dotted line B B' is line of the soffit 
on the bottom bed, the line c c' is the line of 
joint on top bed, the line d d' is the line of 
arris of the arch joint in soffit, and the line 
A A' is the radiating vertical joint. No. 1 A 
(Fig. 12) is the face mould for convex face, 
and No. 1 B, Fig. 12, is the face mould for 
concave face; both of these are transferred 
from 1 A and 1 B (Figs. 10 and 11), with the 
addition of the square line e e r . 

Work the two beds (bottom and top) par¬ 
allel to each other, and of the height of the 
face mould. Scribe the bed mould No. 1 C 
(Fig. 12), on both beds, and work the two 
faces convex and concave through, and also 
the vertical joint A a, which must be at right 
angles to beds; this will form a portion of a 
hollow cylinder similar to sketch, Fig. 7. Now 
scribe in the face moulds 1 A and 1 B (Fig. 12), 
on the convex and concave faces respectively, 
and work the arch joint c d through, and for 
arrises to the lines, and work drafts parallel 
to the bed B B' until the whole of the soffit is finished. 

In this arch the soffit is not a winding surface. 

To work the Second Arch Stone No 2 A {Fig. 10). 

Let No. 2 C (Fig. 13) be the bed mould, project the extreme 
points b h, No. 2 A (Fig. 10), on to springing line AC. This 
being a developed face, it will require folding back on to the 
segment line A C E of plan (Fig 9), as b d h, and transfer this 
to No. 2 C, which gives the bed mould. 

No. 2 A (Fig. 13) is the face mould for convex face, and No. 



FIG.14 


the soffit, cut in 






APPENDIX 


295 


ARCHES CIRCULAR ON PLAN' 























































296 


APPENDIX 


2 B (Fig. 13) is the face mould for concave face, and both of 
these are transferred from 2 A and 2 B (Figs. 10 and 11), with 
the addition of the square line Z. 

Work the two beds (bottom and top) parallel to each other, 
and to the height of the face mould. The bottom bed is worked 
as a surface of operation for the application of the bed mould, 
and it is all cut away except the arris d d '. Scribe the bed 
mould 2 C (Fig. 13) in on each bed, and work the two faces 
convex and concave through, and scribe in the face moulds 2 A 
and 2 B (Fig. 13). 

Work the vertical joint b b square with either the top or bot¬ 
tom beds, and work the bed b c and joint c d; then joint g h, 
and, lastly, soffit dh. 

Fig. 14.— Nos. 3 A, 3 B, and 3 C are the face moulds and bed 
mould of the third arch stone, and together with the keystone 
are projected and worked in precisely the same manner as the 
foregoing Nos. 1 and 2 stones. 

It will be advisable for the student to work small models, 
which should be constructed to scale in plaster, clay, or other 
soft material. The moulds for these models may be cut out of 
stout drawing paper, and in their application will be found the 
best method of obtaining knowledge of these subjects. 

SKEW ARCH AND NICHES 

To construct a Semi-circular Arch Rib, the oblique angle 
of which does not extend more than ten or twelve degrees from 
a right angle, the joints being parallel to axis, and in the same 
planes. 

This is not a. difficult problem, as the arch within these limits 
may be set out and worked as a right arch; but beyond these a 
different principle of construction is necessary. 

Fig. 1 . —Shows the elevation of the arch, which is a semi¬ 
circle. 

Fig. 2.—Shows the plan of the arch, B G and D J being the 
opening, B D and G J the inclination or angle of skew, E and F 
the centers, A and H the outer face line of the arch, and C K 
the inner face line of the arch. 

There is no difference in the outer and inner faces of the arch, 
both being alike, but the terms are here used for purpose of 
explanation. 


APPENDIX 


297 


Project A C, B D and GJ, HK from the plan to the spring¬ 
ing line (Fig. 1), as a c, b d and g j, h k, with e as center, and 
e a and e b as radius, describe the semi-circles a oh and b m g, 
for the outside face, and with / as center, and the same radius, 
describe the semi-circles cpk and d n /, for the inside face. 
For the joints, divide the arch into any convenient number of 
equal parts—in this example seven—as qr stuv on line bm g 
of intrados, and with the same divisions repeat on the line dnj 


SKEW ARCH 


ELEVATION 



FIG.2. 
PLAN 


as q' r' s' t' u' v'; from the center e draw radiating lines through 
these points, and produce to the outside curve or extrados for 
the outside, and for the inside of the arch; repeat the same from 
the center /. It will be observed that the direction of joints is 
perfectly horizontal, the lines q q', rr', ss ', etc., being level; 
the radiating lines and joints are also parallel to each other, 
and are therefore in the same place. 

This is all the setting out required, with the exception of the 
joint moulds. 

























298 


APPENDIX 


To work the Arch Stones. 

Fig. 3.—Let No. 1 L be the face mould of the springer and 
A and B the joint moulds. 

The face mould 1 L is transferred from the elevation Fig. 1, 
and the bottom bed or joint mould A, from plan (Fig. 2); for the 
joint mould B, draw a line parallel to joint e' /', and project 
e' /' and g f h' as e f and g h , of an equal and parallel thickness, 
as X X at A and B. 

Work a' b' e' /' outside face of springer No. 1 L, to a plane 
surface, and cdgh inside, face parallel to it; scribe the face 
mould into extreme size on each face as a' d! e' g' h'; scribe in 
the segment line /' b' } giving arris of soffit on outside face (this 
may be done by drawing the mould back, as h'd' is the same 
segment and also the same length as /' b') 



Work the bottom bed A, which is horizontal, and square with 
the vertical faee, and scribe in the bed mould as abed , which 
will coincide with the lines' on the face mould; now work the 
top joint B; this from the outside face will be full of the square, 
or, in other words, it makes an obtuse angle with the vertical 
face. This, however, is given by the face mould, as e' /' is line 
of joint on the outside, and g' h' on the inside. 

Scribe in the joint mould B as e / g h, and work the soffit 
b'd! /' h' through, as in a right arch, and finish with the back 
joint a' e' e' g'. 

Fig. 4. —No. 2 L is worked similar to No. 1 L; the top joint 













APPENDIX 


299 


mould B of No. 1 is the bottom joint mould of No. 2, and the 
top joint mould C of No. 2 is the bottom joint mould of No. 3, 
and so on—this is self-evident. The bevels of these joints are 
found by projecting the points of the face mould, as j k l m, 
etc., as before described. 

Begin by working the two vertical faces e f j k and g him 
parallel to each other, scribe in the face mould No. 2 to the 
extreme size, as e f h j l m, and work both joints B and C; the 
top joint C is full of the square, whilst the bottom joint B is 
slack of the square from the outside face, the amount of the 
obtuse and acute angle being given on the face mould. 

Fig. 5. —No. 3 L and the keystone are worked precisely simi¬ 
lar to the foregoing. 

One set of moulds for one-half of the arch only is required, 
as the four face moulds and the four joint moulds will work the 
complete arch; being a plain arch without mouldings, the stones 
are reversible; this is apparent on looking at the elevation, but 
should there be an architrave moulding on one face, a mould 
to each stone is then required. 

To construct a Spherical Niche in a straight wall with hori¬ 
zontal splay beds, and with vertical joints. 

Figs. 6 and 7. —Show the elevation and plan of the niche. 

Let A E be the face line of the niche on plan (Fig. 7), B D 
the opening and C the center; with C B or C D as radius, and 
C as center, describe a semi-circle BKD, which is plan of ex¬ 
treme size of inside of niche; project A B C D E to the spring¬ 
ing line on elevation (Fig. 6), as ah c de, and at c erect perpen¬ 
dicular for the center line. With c as center and c 6 or c d as 
radius, describe the semi-circle b k d for the outer curve, and 
divide this into five equal parts as at / g h i; from c draw radiating 
lines through these points of division, cutting the horizontal 
bed at Imno, giving the joints, the bevel of which will be con¬ 
tinued horizontally round the niche as at / i and g h. For joints 
to the plan draw ordinates at fghi and l m, etc., and project 
them on to line A E on plan (Fig. 7), as F G H I and L M, etc.; 
at L F M G describe the semi-circles, giving the horizontal line 
of splay joints. For dividing joints on the plan, take the second 
course first and divide the line of semi-circle F Q I into four 
equal parts as P Q R, and from C draw radiating lines through 
these divisions, producing them on to the line L N O, which 
gives the joints. The springers 1 L and 1 R in the first course 


300 


APPENDIX 


will require to be about half the depth of others in the same 
course, in order to break the bond (as will be seen by reference 
to the plan); therefore, on the line B K D, set off, say, little 
more than half for the two springers as B S and D V, dividing 
the remainder into three equal parts as at S T U V, and draw 
the lines through, radiating from the center to the back, giving 
the joints in the bottom course. 



The top course No. 3 is in one stone, and to prevent any tend¬ 
ency to slip out of its place forward, the upper part of bed may 
be kept square; this would require notching on the inside, as 
M 2 and N M 2 on the plan, and m 4 4 and ra 5 5 on the ele¬ 
vation. 

The vertical joints are shown on the elevation by projecting 
up from the plan, as shown by the dotted lines w p x q, etc. 



































APPENDIX 


301 


To work the Springer. 

Fig. 8.—1 A is the bed mould transferred from the plan (Fig. 
7), the line A F being the vertical face on the front, F W the 
horizontal line of arris of soffit and splay joint on the top bed, 
L O the outside line of splay joint on top bed, the dotted line 
B S the line of soffit on bottom bed, W W' the line of vertical 
radiating joint, and A A' the line of vertical face joint. 

1 L is the face mould transferred from the elevation (Fig. 6), 
which will also apply as joint mould at W“W\ 

The form of the stone required to work this will be a wedge- 
shape prism, containing the bed mould to the extreme size on 
the top bed as AFWW'; the bottom bed is a little smaller, 
and is contained within the lines A B S W', and of the extreme 
height of the face mould from a to a'. 





Begin by working the front vertical face ABF, and scribe 
the face mould 1 L on, as ah f la'. Work the vertical joint 
A A' as a a' square with the front face, and bottom and top 
beds square with the front face, scribing on the bed mould 1 A, 
and also the inside vertical joint W W', scribing in the face 
mould as ah f la'. It is necessary to work the whole of the 
top bed, although a portion from l to / 1 will be cut away for 
the splay joint, in order to get horizontal line F W at /; to obtain 
this arris, square down the concave line from F to W to the 
depth at /, or a draft from F to W may be worked by the aid 
of a template. This being done, trammel the line / parallel to 
/1, giving the arris line required; the line L O is marked on the 

















APPENDIX 


502 

top bed with the template, and the splay joint from f to l then 
worked off. The soffit now remains to be worked; cut in the 
drafts B S on the bottom bed and F W on the top bed, and 
drafts b f on the face and joint; a convex template is used as at g 
for the intermediate drafts, which are cut in as close as con¬ 
venient, until the whole surface is worked. 

The template g must not be applied parallel to the joints, but 
to lines radiating from the center. 

The three No. 4 stones will be worked similarly to the fore¬ 
going; one vertical joint is worked first as a surface of operation, 
instead of the front face as in the springer. 

To work No. 2 L Stone. 

Fig. 9.—2 B is the bed mould transferred from the plan (Fig. 
7), the line B G being the vertical face on the front, and G Y 
the horizontal line of the arris of soffit and the splay joint on 
the top bed, M M' the outside line of the splay joint top bed, 
the dotted line F P the line of soffit on bottom bed, Y Y / the 
line of vertical radiating joint, and B B' the line of vertical 
face joint. 

2 L is the face mould, transferred from the elevation (Fig. 6), 
which will also apply as joint mould at Y Y'. 

The form of stone required to work this will be a wedge-shape 
prism, containing the bed mould, to the extreme size as B G 
Y Y 1, and of the extreme height of the face mould, from / 1 
to b 1. 

Begin by working the front vertical face, and scribe the face 
mould 2 L on as b 1 b f g m. Work the vertical joint b b' square 
with the front face, also the top bed, and scribe the bed mould 
on. Work the bottom bed as a surface of operation; the only 
part required being the arris of the splay joint, and soffit F P, 
the rest of the bed being cut away. 

This is the easiest and most accurate way of working, but 
the bed need not necessarily be worked as a whole, a portion 
only being required, sufficient to obtain the arris line F P; in 
this case the soffit F G should be worked after the arris line is 
drawn on the bed, by a convex template made from / to g, and 
the splay joint is worked from a beveled template made from 

gfb- 

The remaining portion of the stone is worked as before de¬ 
scribed to springer. 

The two No. 5 stones are worked similarly. 


APPENDIX 


303 


To work the Keystone No. 3. 

Fig. 10.—3 C is the bed mould transferred from the plan 
(Fig. 7), the line MN being the vertical face on the front, 
M C 2 N the top line of the splay joint, and G C 1 H the line 
of arris of soffit, and the splay joint on bottom. 

No. 3 is the face mould transferred from the elevation (Fig. 6), 



Begin by working the vertical face M N, scribing in the face 
mould as ghmn. Work the top bed through square with the 
face, scribing in the bed mould, also the bottom bed parallel 
to the top at extreme points g and h, and with a template scribe 
G C H the arris of the soffit and the splay joint. Work the 
joint round tc the splay lines, then the soffit by cutting in the 
draft g c h on the front, and with a convex template made from 
C to Cl, complete the surface. 












































m 


APPENDIX 


The niche need not be jointed as here shown, for much de¬ 
pends on its size, and the size of the stone convenient to use, 
but the general principle of working will be the same. 

To construct a Spherical Niche in a straight wall, with joints 
radiating from the center. 

Figs. 11 and 12. —Show elevation and plan of the niche. 

Let A E be the vertical face line of the niche on the plan (Fig. 
12), B D the opening, and C the center. With C B or C D as 
a radius, and C as a center, describe the semi-circle, B K D, which 
is the plan of extreme size of the inside of niche, and project 
A B C D E to the springing line a Q on the elevation (Fig. 11), 




as ah c de. At c erect a perpendicular for the center line, and, 
with c as center and c b or c d as radius, describe the semi-circle 
b k d for the outer curve. With c y as a radius and c as the cen¬ 
ter, describe a semi-circle for the center stone, which may be 
of any convenient size. Divide the semi-circle b k d into 
seven equal parts as / g hi j l, and through these points of 
division from c draw radiating lines cutting horizontal beds 
at m n o p, etc., and the center stone at s t u v, etc., 
which gives the joints. Draw ordinates from f g h i, etc., 
and project on to the line A B as F G H I, etc., and repeat 
the same at stuv, etc., on the line Y Z, giving joint lines on 
the plan; to determine points in the curve of the soffit for templates, 
the dotted lines at the right hand of the niche show how they 










APPENDIX 


305 


are obtained. The dotted segment line from 1 to 1, 2 to 2, 
3 to 3, etc., on elevation will be the section of curve at corre¬ 
sponding points on the plan at 1 1, 2 2, 3 3, etc., and also gives 
the points in the line of curve for the joints on plan, although 
the last named is not necessary for the setting out or the work¬ 
ing. 

To work the Springer 1 L. 

Fig. 13.—1 A is the bed or joint mould transferred from the 
plan (Fig. 12), the line A B being the front vertical face, B Y 
the line of soffit, Y Y 1 the splay joint, and A A 1 the vertical 
face joint. 

No. 1 L is the face mould transferred from the elevation (Fig. 

11 ). 

The form of stone required will be that of a wedge-shape 
prism (as in sketch, Fig. 14), containing the face mould to the 
extreme size as a' ay s m. 

Begin by working the bed or joint ah y, keeping the seg¬ 
mental line B Y fair for arris, and scribe the bed mould 1 A on. 
Work the vertical face and scribe in the face mould 1 L, and 
the other bed m / s, scribing in the bed mould 1 A. Work the 
vertical joint a a', and top bed o' m , and, lastly, the soffit, the 
working of this being guided by one or two templates made from 
11,2 2, etc. 

The remaining stones are worked similar to the foregoing, 
keeping in mind the principle that the stone is contained within 
the wedge-shape prism, thus making it easy of comprehension 


THE 20 TH CENTURY BRICKLAYER’S AND 
MASON’S ASSISTANT. 

The student will be expected to read carefully these 
papers before doing any work. His name and ad¬ 
dress will require to be given on each paper. He will 
be expected to write up the questions in a neat and in¬ 
telligent manner, using his own language and style, rep¬ 
resenting the answers in such a manner as will be in¬ 
telligible—make all drawings as clear as possible, and 
wherever it can be done render them in India ink. Let 
each answer be original, do not copy either from the in¬ 
struction papers nor from any other source. The paper 
used may be of any kind, provided that it is clean and 
durable. Do not attempt an answer until you have 
thoroughly grasped the subject. 

QUESTIONS. 

1. Give a definition of what is meant by a “plan” 
of a wall or building. 

2 . Give a definition of what is meant by an “eleva¬ 
tion” of a building. 

3 . Give a definition of what is meant by a “section” 
of a wall or building. 

4 . Give a definition of what is meant by a “course” 
of brick work. 

5 . Give a definition of what is meant by the “bed 
joint” in brick work. 

6 . Give a definition of what is meant by the “cross 
joints” in brick work. 

306 


QUESTIONS 307 

7 . Give a definition of what is meant by the “trans¬ 
verse joints” in brick work. 

8 . Give a definition of what is meant by “wall joints” 
in brick work. 

9 . Give a definition of what is meant by “quoins” in 
brick work. 

10 . Give a description of what is meant by the 
“stretcher” in brick walls. 

11 . Give a description of what is meant by the 
“header” in brick walls. 

12 . Give a description of what is meant by the “bats” 
in brick work. 

13 . Give a description of what is meant by the “lap” 
in brick work. 

14 . Give a description of what is meant by a “king 
closer” in brick work. 

15 . Give a description of what is meant by a “queen 
closer” in brick work. 

16 . Give a description of what is the average length, 
width and average thickness of a brick, also state what 
is the usual practice in building curves, and the thick¬ 
nesses given to walls i l /2 bricks, 2^4 bricks, 2 bricks, 
and three bricks thick, respectively. 

17 . Give a description of the use of foundations in 
brick structures of any kind. 

18 . Give a description of some of the “damaging 
forces” that cause failures in the construction or stability 
of foundations. 

19 . Give a description of what causes “inequality of 
settlement” in foundations. 

20 . Give a description of what is meant by the “lateral 
escape” in heavy structures. 

21 . Give a description of what is meant by the defect 


3°8 


BRICKLAYERS’ GUIDE 


called “sliding” in a wall or building, and how this is 
prevented. 

22. Give a description of what might happen on the 
withdrawal of water from the foundation earth, and how 
this may be prevented. 

23. Give a description of the “distributed overturn¬ 
ing pressure” upon walls. 

24. Give a description of the “concentrated lateral 
pressure” upon walls. 

25. Give a description of the “atmospheric action” 
upon foundations and what must be done to prevent this. 

26. Give a description of what must be done before 
commencing any constructional work in connection with 
a building. 

27. Give a description of the three methods of “Lev¬ 
eling.” 

28. Give a description of the “Boning” method of 
“Leveling.” 

29. Give a description of the work of excavating the 
trenches, and known by the term “trenching.” 

30. Give a description of the method of forming an 
embankment. 

31. Give a description of “timbering for excavations” 
for foundations or other purposes. 

32. Give a description of the operations employed, in 
“large cuttings” in trenches. 

33. Give a description in sinking “shafts” for foun¬ 
dations. 

34. Give a description of “tunneling” in building 
operations. 

35. Give a description of the ordinary soils met with 
in laying foundations and the method of treating each. 


QUESTIONS 309 

36. Mention some cases that require special treat¬ 
ment in laying foundations. 

1 37. Give a description how to prepare footings on 
which to lay bricks, and sketch illustrating same. 

38. Give a description of the different kinds of “damp 
courses,” and their application in building purposes. 

39. Give a description of what is known as the “dry 
area method” of preventing damp from getting into a 
wall, by building a dwarf wall, and illustrate same by 
sketch. 

40. Give a description of how to cure a damp build¬ 
ing, when it has been erected without a damp course. 

41. Give an effective prescription which may be ap¬ 
plied to outside walls to prevent damp. 

42. Give a few illustrations and descriptions of cop¬ 
ings that may be used for brick walls. 

43. Give a description of “brick corbeling” as used 
in brick walls. 

44. Give a description and a few illustrative sketches 
showing several styles of “moulded brick cornices.’* 

45. Give a description and illustrative sketch show¬ 
ing the formation of “brick pilasters” in brick walls. 

46. Give a description and illustrative sketch show¬ 
ing how to form panels in brick walls. 

47. Give a description of what is meant by the term 
“Bonding” in brick work. 

48. Give a description of what is meant by “English 
Bond” in brick work, with sketch. 

49. Give a description of “Double Flemish Bond” 
with sketch. 

50. Give a description of “Single Flemish Bond” 
with sketch. 

51. Give a description of “English Cross Bond” with 
sketch. 


3io 


BRICKLAYERS’ GUIDE 


5 2. Give a description of “Dutch Bond” with sketch. 

53. Give a description of “Sketching Bond.” 

54. Give a description of “Country or garden wall 
bond” with sketch. 

55. Give a description of “heading bond.” 

56. Give a description of what is meant by the term 
“lacing courses” in brick walls. 

57. Give a description of what is termed “Hoop-iron 
bond” in brick work. 

58. Give a description of what is termed “Raking 
Bond” in brick work. 

59. Give a description of what is termed “Diagonal 
Bond” in brick work, and sketch illustrating same. 

60. Give a description of what is termed “Herring- 
Bone Bond” with sketch illustrating same. 

61. Give a description of how the bond is obtained at 
the junction of cross walls, and sketches illustrating same. 

62. Give a description of splayed jambs, and sketches 
illustrating same. 

63. Give a description of “squint quoins,” and several 
sketches illustrating same. 

64. Give a description of “toothing” in brick walls and 
sketches illustrating same. 

65. Give a description of what is meant by the term 
“racking” in brickwork, and sketch illustrating same. 

66. Give a description of how leveling of brickwork 
should be done. 

67. Give a description of the different “joints” used 
in brickwork. 

68. Give a description of the formation of fireplaces 
in brickwork, and show sketch how flues or vents are 
formed in brick gables. 


QUESTIONS 


3ii 

69. Give a description of the mode of carrying the 
hearth, and sketch illustrating same. 

70. Give a description of corbeling in brickwork. 

71. Give a description of “bond in chimney stacks” 
and illustrative sketches of same. 

72. Give a description of “Setting Ranges” in brick¬ 
work, with sketches of same. 

73. Give a description of the “relieving arch” in brick 
work, and show sketch illustrating same. 

74. Give a description of the “invert arch” and sketch 
illustrating same. 

75. Give a description of how to form an egg-shaped 
sewer, and sketch illustrating same. 

76. Give a description of the formation of “axed 
arches” in brickwork. 

77. Give a description of the formation of the “Semi¬ 
circular brick arch” and sketch illustrating same. 

78. Give a description of the formation of an arch 
with moulded soffit in brickwork. 

79. Give a description of the formation of the seg¬ 
ment arch in brickwork. 

80. Give a description of the formation of a moulded 
segment arch in brickwork. 

81. Give a description of the formation of the camber 
arch in brickwork. 

82. Give a description of how to form the equilateral 
or Gothic arch in brickwork, with sketch illustrating 
same. 

83. Give a description of how to form the modified 
Gothic arch, with sketch illustrating same. 

84. Give a description of how to form the elliptical 
arch in brickwork, and show sketch illustrating same. 

85. Give a description of how to form the “Bulls- 


3 12 


BRICKLAYERS’ GUIDE 


eye arch” in brickwork, and show sketch illustrating 
same. 

86. Give a description of the “semi-Gothic arch” in 
brickwork, having a semi-circular intrados, but a Gothic 
extrados, and show sketch illustrating same. 

87. Give a description of the “Horse-Shoe or Moor¬ 
ish arch” in brickwork, and sketch illustrating same. 

88. Give a description of how to form arches in 
brickwork that spring from the same pier but differ in 
size, and sketch illustrating same. 

89. Give a description of the formation of “the semi¬ 
circular niche” in brickwork, and sketch illustrating 
same. 

90. Give a description of how the “oriel window” is 
constructed with brickwork, and sketch illustrating same. 

91. Give a few general remarks introductory to the 
study of Mason’s work. 

92. Give the meaning of the technical terms “Bond,” 
“Lap” and “course” used in Mason’s work. 

93. Give the meaning of the term “Through stones” 
employed in mason’s work. 

94. Give the meaning of the term “Headers” in ma¬ 
son’s work. 

95. Give the meaning of the term “Bonders” in ma¬ 
son’s work. 

96. Give the meaning of the term “Grout” used in 
mason’s work. 

97. Give the meaning of “Spalls or Shivers” used in 
mason’s work. 

98. Give the meaning of the term “weathering” used 
in mason’s work. 

99. Give the meaning of the term “Footings” used 
in mason’s work. 


QUESTIONS 


3i3 

100. Give the meaning of the term “Bed-Surface” 
used in mason’s work. 

101. Give the meaning of the term “Galleting” used 
in mason’s work. 

102. Give the meaning of the term “Dressings” used 
in mason’s work. 

103. Give a description of the term “Quoins” used 
in mason’s work. 

104. Give a description of the term “sills” used in 
mason’s work. 

105. Give a description of what is meant by a “corbel” 
in mason’s work. 

106. Give a description of what is meant by a “skew 
corbel” in mason’s work. 

107. Give a description of the term “string courses” 
used in mason’s work. 

108. Give a description of “saddled or water joint” 
used in mason’s work. 

109. Give a description of the term “blocking course” 
in mason’s work. 

no. Give a description of the term “coping” used in 
mason’s work. 

in. Give a description of seven different kinds of- 
wrought stone, and the names by which they are desig¬ 
nated. 

112. Give a general description of “rabble masonry.” 

113. Give a description of what is meant by “random, 
common, or rough rubble,” “square uncoursed,” “random 
coursed,” “irregular coursed,” “snecked or squared 
rubble,” respectively, and show sketch illustrating same. 

114. Give a description of what is meant by “ashlar 
work” used in mason’s work. 

115. Give a description of what is meant by “rubble 
ashlar” used in mason’s work. 


3H 


BRICKLAYERS’ GUIDE 


116. Give a description of what is meant by the term 
“bond” in mason’s work. 

117. Give a description of the different “joints” used 
in the building of mason’s work. 

118. Give a description of the process of “rebating” 
in mason’s work. 

119. Give a description of the process of “joggling” 
in mason’s work. 

120. Give a description of the process of “doweling” 
in mason’s work. 

121. Give a description of the process of “lead 
plugging” used in mason’s work. 

122. Give a description of “dovetail bonding” used in 
mason’s work. 

123. Give a description of “tabling” used in mason’s 
work. 

124. Give a description of the names applied to differ¬ 
ent parts of “an arch” in mason work, and show sketch 
illustrating same. 

125. Give a description of the method of setting out 
and drawing the joints of a semi-oval arch approaching 
in form that of the ellipse, with illustrative sketch. 

126. Give a description of the method of setting out 
and drawing the joints of a Tudor arch, based on the 
curve of the hyperbola, with illustrative sketch. 

127. Give a description of the method of setting out 
and drawing the joints of a Tudor arch with a parabolic 
curve, and show illustrative sketch. 

128. Give the names and descriptions of the three 
joints used in landings, with illustrative sketch. 

129. Give the names of various bed joints in stone 
spires, with illustrative sketch. 

130. Give a description of the different kinds of 
stone stairs and steps, also stone landings. 


QUESTIONS 315 

131. Give a description of “fixing the steps” and how 
the walls should be prepared for their reception. 

132. Give a description of the method of forming a 
stone covered roof over a vaulted chamber, with illus¬ 
trative sketch. 

133. Give the names and descriptions of the two heads 
under which “mouldings” may be classified. 

134. Give a description of the “fillet” and a drawing 
of same. 

135. Give a description of the “astragal” and a draw¬ 
ing of same. 

136. Give a description of the “cavetto” and a draw¬ 
ing of same. 

137. Give a description of the “ovolo” and a drawing 
of same. 

138. Give a description of the “cyma recta” and a* 
drawing of same. 

139. Give a description of the “cyma reversa,” and a 
drawing of same. 

140. Give a description of the “Scotia” and a draw¬ 
ing of same. 

141. Give a description of the “Torus” and a draw¬ 
ing of same. 

142. Give a description of the “Bird’s Beak” and a 
drawing of same. 

143. Give the names and descriptions of those 

mouldings that are termed “crowning mouldings.” 

144. Give the names and descriptions of those 

mouldings that are termed “supporting mouldings.” 

145. Give the names of those mouldings that are 
termed “connecting mouldings.” 

146. Give a drawing of the “Roll and Shallow Hol¬ 
low” moulding of the Gothic period. 


3 j 6 


BRICKLAYERS’ GUIDE 


147. Give a drawing of the “Roll and Triple Fillet” 
moulding of the Gothic period. 

148. Give a drawing of the “Plain Bowtell” mould¬ 
ing of the Gothic period. 

149. Give a drawing of the “Pointed Bowtell” 
moulding of the Gothic period. 

150. Give a drawing of the “Scroll Moulding” of 
the Gothic period. 


BRICKLAYERS’ GUIDE 


A 

Atmospheric action, 16 

Asphalt damp courses, 43 

Acute squints, 81 

Angles of walls, 83 

Arches and gauged work, 99 

Arches generally, 101 

Axed arches, 105 

Arches with moulded soffit, 112 

Arches springing from one pier, 137 

About niches, 138 

B 

Bed joints, 12 
Bats, 12 

Bonding method of leveling, 21 
Bonding walls, 51 
Bonding for fireplaces, 52 
Best double wall construction, 53 
Brick cornices, 60 
Brick columns, 61 
Brick capitals, 61 
Base of columns, 62 
Bonding generally, 67 
Bond, “What is it?” 67 
Bond in brickwork, 67 
Brick reveals, 79 
Bastard tack pointing, 87 
Breasts and flues, 88 
Bond in chimney stacks, 94 
Bull’s-eye arch, 133 
Bricklayer’s tools, 158 
Brick cutting tools, 160 
Bricklayer’s mortar, 161 
Building in frosty weather, 161 
Brown mortar, 163 
Bricks specified, 164 
Bricklayer’s specifications, 164 
Brickwork during frost, 177 

C 

Course, 12 
Cross-joints, 12 
Closers, 12 

Concentrated lateral pressure, 16 
Clay, 36 

Circular damp protection, 45 
Cavity walls, 54 
Copings, 58 
Corbels, 59 
Cornices, 60 

Chimney breasts and flues, 88 
Chimneys of various kinds, 90 
Chimney bond, 93 


Clustered flues, 96 
Cutting bricks, 100 
Construction, 106 
Camber arch, 117 
Camber on circle, 122 
Curved work, 123 
Cubic measurement, 148 
Concrete, 152 
Cubing, 149 
Chimney breasts, 155 
Course mortar, 162 
Colored mortar, 162 

D 

Damaging forces, 14 

Distributed over-turning pressures, 16 

Damp courses, 40 

Double wall damp courses, 46 

Dry areas, 48 

Damp walls, 54 

Damp outside walls, 56 

Dutch bond, 69 

Double flemish bond, 70 

Diagonal bond, 76 

Double flues, 89 

Drawing arches, 129 

Damp-proof walls, 175 

Drainlayer, 178 

Drainage, 180 

E 

Excavation, 17 

Embanking, 23 

English bond, 68 

English cross bond, 69 

Examples of single Flemish bond. 72 

Egg-shaped sewer, 104 

Equilateral Gothic arch 125 

Elliptical arch, 127 

Estimating quantities, 150 

Enameled bricks, 165 

F 

Foundations, 13 
First method, 18 
Foundations, 35 
Forms of foundation, 39 
Flemish bond, 69 
Facing bond, 73 
Flat or flush joints, 85 
Flat jointed joints, 85 
Flues, etc., 88 
Fireplace jambs, 91 
Fixing and setting niche, 14? 


1 


STONEMASONS’ GUIDE 


A 

A stonemason—What is he? 181 

Axed work, 190 

Ashlar, 196 

Ashlar rubble, 236 

Ashlar facings, 235 

Arches and joints, 246 

Ashlar, 283 

Appendix, 287 

Arches, circular or plain 288 
A stone niche, 300 

B 

Bond, tap, and course, 182 
Bonders, 182 
Bed surface, 183 
Blocking course, 185 
Breasted work, 190 
Block in course, 195 
Bolts, 199 
Bond, 238 

C 

Corbel, 184 

Cornices, 185 

Coping, 185 

Corbel step gables. 186 

Corbel table, 186 

Chisel drafted margin 189 

Combed or dragged work, 191 

Circular work, 193 

Circular sunk work, 193 

Circular circular sunk work, 193 

Cramps, 198 

Cement joggles, 200 

Curved beds, 218 

Coping stones, 231 

Cornice caps, 253 

Classic mouldings, 272 

Crowning mouldings, 275 

Carving, 284 

D 

Diaper work, 187 
Dowels, 200 
Dry rubble, 233 
Doweling, 241 
Dovetail bonding, 242 
Definitions, 245 
Dovetail joints, 252 
Dressings, 282 
Developments, 288 

E 

External miters, 173 

Elevations and sections of stone walls. 257 


Elevations, plans, and sections of windows, 258 
Elevations of circular window heads, 259 
Elevations of sunk work, 260 
Elevations of square windows, 261 
Elevations and plan of Gothic windows, 262 
Elevations and sections of Gothic doorway, 
264 

Elevation and plan of niche, 300 
F 

Footings, 183 
Finial, 187 
Furrowed work, 191 
Flush joints, 239 
Flat arches, 248 
Fixing stone steps, 267 
Floors and steps, 284 

G 

Grout, 182 
Galleting, 183 
Gable details, 186 
Gablets, 186 
Gargoyle, 187 
Gothic window heads, 262 
Gothic joints, 263 
Grecian mouldings, 272 
Gothic mouldings, 273 

H 

Headers, 182 

Half-sawing, 188 

Hammer dressing, 189 

How to work a stone niche, 303 

I 

Introduction, 181 
Internal miters, 193 
Irregular rubble. 236 

J 

Joints, 196 

Joints to resist compression, 198 

Joints to resist tension, 198 

Joints to resist sliding, 199 

Joggles, 199 

Joints 238 

Joggling 241 

Joggle joints, 249 

K 

Kneeler or skewput, 184 
Keystones in circular windows, 260 
Keystones in square window heads, 261 


1 


INDEX 


• • 
1! 


L 

Lacing courses, 184 

Lintels, 187 

Labors, 188 

Lead plugs, 199 

Lewis bolts, 206 

Large face moulds, 218 

Large block ashlar, 226 

Lead plugs, their use, 242 

Lewis bolts, 256 

Laying out a stone niche, 803 

M 

Moulded work, 192 
Moulded work, circular, 193 
Mixed masonry, 223 
Masonry generally, 224 
Moulded Gothic windows, 262 
Mouldings, classic, 272 
Materials, 276 
Mechanical engineer, 277 

0 

Open joints, 240 
Other special clauses, 285 
Other arches, 286 
Open arches, 288 

P 

Plinth, 185 
Parapet, 187 
Plain work, 189 
Polishing, 190 
Pointed work, 192 
Pebbles, 201 

Protecting cut-stone work, 243 

Q 

Quoins, 183 

R 

Rebated joint, 185 

Rubbed work, 189 

Returned, mitered and stopped, 193 

Random rubble, 194 

Random rubble set dry, 194 

Random rubble in course, 195 

Regular coursed rubble, 195 

Rag bolts, 199 

Rubble masonry, 220 

Rebated V-joints, 228 

Rough hammered work, 229 

Rubbed work, 230 

Raking copings, 231 

Rubble ashlar, 234 

Rusticated joints, 240 

Rebating, 240 

Radius, 245 

Roman mouldings, 272 

S 

Sparks or shivers, 182 
Stanchions, 184 
Sills, 184 

Saddle or apex stone, 184 


Skew corbel, 184 
String courses, 185 
Saddled or water joints, 185 
Self-faced, 189 
Scabbling or scappling, 189 
Sunk work, 193 
Stone walling, 194 
Snecked rubble, 195 
Squared rubble, 195 
Stone-cutting saw, 206 
Spatting hammer, 210 
Snecked rubble, 237 
Securing bolts, 243 
Springer, 244 
Skewbacks, 244 
Span, 245 

Stone steps and stairs, 266 
Spiral stairs, 269 
Stone roof, 270 
Stone vaulting, 271 
Specification clauses, 276 
Stone-worker’s specifications, 279 
Special clauses for a church, 282 
Sundries, 284 
Skew arch, 297 

T 

Technical terms, 182 
Through stones, 182 
Throatings, 186 
Templates, 186 
Tympanum, 187 
Tailing irons, 187 
Tooled work, 190 
Tabbing joints, 200 
Tools and appliances, 201 
Tools used in masonry, 202 
Traceried Gothic windows, 262 
Tracery, 265 
To work arch stones, 289 
To scribe stones, 290 
To set up elevations, 293 

U 

Unwound random rubble, 194 
Unwound snecked rubble, 195 
Under-surface, 244 

v 

Vermiculated work, 191 
Voussoirs, 244 
Vaults, 271 
Vaulted roofs, 271 
Vaulting, 282 
Vertical joints, 282 

W 

Weathering, 182 
Window and door jambs, 183 
Wrought stone names, 212 
Window sills, 231 
Window heads, 231 
Winding stairs, 268 
Workmanship, 277 


6 


CEMENTS AND CONCRETES 


ment, furnished me on application, and from materials 
gathered from many sources, and, while I have added 
considerable from my own knowledge of the subject, 
it may be said that the work is almost a compilation 
taken from the best authorities on the subjects dis¬ 
cussed. 

There is enough material on the subject of concrete 
floating about in the technical press, of the best kind, 
to build up three or four volumes of the size of this 
one, but, in analyzing it, I have sifted it down to the 
limits of this book, preserving that, which in my judg¬ 
ment, was best for the practical worker, and leaving out 
the most of that which might be termed theoretical and, 
therefore, to a large extent unfit for artisans’ purposes. 
In making the selections in matters of this kind, the 
personal factor must necessarily be of more or less 
value, and I flatter myself that, after a successful build¬ 
ing experience in various forms, covering a period of 
over fifty years, my knowledge of the value of any 
problem pertaining to the building trades is deserving 
of considerable respect. It is this knowledge, along 
with some knowledge of cause and effect, and my simple 
and unvarnished methods of placing building matters 
before the American workmen, that have made my 
books so popular, and lured the working public into pur¬ 
chasing, at this writing, nearly two millions of them. 
And I have reason to hope that this volume will, like 
all my previous ones, meet with a reasonable amount 
of appreciation from those who work, or guide the work 
of others, in cements, plasters, concretes and stuccos. 

Fred T. Hodgson. 


PART I 


CONCRETES, CEMENTS, PLASTERS AND STUC¬ 
COS—THEIR USES AND METHODS 
OF WORKING S AM E. 

INTRODUCTORY 

This book, or rather compilation, is largely made up 
of the very best material available on the subjects it 
proposes to discuss. All the latest improvements and 
methods in the mixing, proportioning and application 
of plaster, mortar, stucco and cement will be described 
and laid before the reader in as simple and plain a man¬ 
ner as possible. 

The art of using mortars in some shape or other, is 
as old as civilization, as we find evidences of its use in 
ruins that date long before historical times, not only 
in the older countries of Asia and Europe, but also in 
the ruins of Mexico, Central America and Peru; and 
the workmen who did their part, or most of this work, 
were evidently experts at the trade, for some of the 
remains of their work which have come down to us 
certainly show that the work was done by men who 
not only had a knowledge of their trade, but that they 
also possessed a fair knowledge of the peculiar qualities 
of the materials they used. “Plastering,” says Miller 
in his great work on Mortars, “is one of the earliest 
instances of man’s power of inductive reasoning, for 
when men built they plastered: at first, like the birds 
and the beavers, with mud; but they soon found out a 
more lasting and more comfortable method, and the 

7 


8 


CEMENTS AND CONCRETES 


earliest efforts of civilization were directed to plaster¬ 
ing. The inquiry into it takes us back to the dawn of 
social life until its origin becomes mythic and prehis¬ 
toric. In that dim, obscure period we cannot pene¬ 
trate far enough to see clearly, but the most distant 
glimpses we can obtain into it show us that man had 
very early attained almost to perfection in compound¬ 
ing material for plastering. In fact, so far as we yet 
know, some of the earliest plastering which has re¬ 
mained to us excels, in its scientific composition, that 
which we use at the present day, telling of ages of ex¬ 
perimental attempts. The pyramids of Egypt contain 
plaster work executed at least four thousand years ago 
(some antiquaries, indeed, say a much longer period), 
and this, where Avilful violence has not disturbed it, 
still exists in perfection, outvying in durability the 
very rock it covers, where this is not protected by its 
shield of plaster. Dr. Flinders Petrie, in his ‘Pyra¬ 
mids and Temples of Gizeh,’ shows us how service¬ 
able and intelligent a co-operator with the painter, the 
sculptor, and the architect, was the plasterer of those 
early days, and that to his care and skill we owe almost 
all we know of the history of these distant times and 
their art. Indeed the plasterer’s very tools do yet re¬ 
main to us, showing that the technical processes then 
were the same we now use, for there are in Dr. Petrie’s 
collection hand floats which in design, shape and pur¬ 
pose are precisely those which we use today. Even our 
newest invention of canvas plaster was well known 
then, and by it were made the masks which yet pre¬ 
serve on the mummy cases the lineaments of their occu¬ 
pants. ’ ’ 

The plaster used by the Egyptians for their finest 
work was derived from burnt gypsum, and was there- 


INTRODUCTORY 


9 


fore exactly the same as our “plaster of paris.” Its 
base was of lime stucco, which, when used on partitions, 
was laid in reeds, laced together with cords, for lath¬ 
ing, and Mr. Miller, who has examined a fragment in 
Dr. Petrie’s collection, finds it practically “three coat 
work,” about % of an inch thick, haired and finished 
just as we do now. 

Plaster moulds and cast slabs exist, but there does not 
appear any evidence of piece moulding, nor does any 
evidence of the use of modelled work in plaster exist. 
That some process of indurating plaster was thus early 
known is evidenced by the plaster pavement at Tel-el 
Amarna, which is elaborately painted. The floor of 
this work is laid on brick; the first coat is of rough 
lime stucco about 1 inch thick, and the finishing coat 
of well-haired plaster about % inch thick, very smooth 
and fine, and showing evidence of trowelling, the set¬ 
ting out lines for the painting being formed by a struck 
cord before the surface was set, and the painting done 
on fresco. It is about 60 by 20, and formed the floor 
of the principal room of the harem of King Amenhotop 
IV., about fourteen hundred years before Christ, that 
is, between three thousand and four thouLand years 
ago. Long before this, plastering of fine quality 
existed in Egypt, and so long as its civilization con¬ 
tinued it aided the comfort of the dwellings of its 
people and the beauty of its temples. 

Nor was it merely for its beauty and comfort that 
plaster work was used. Even then its sanitary value 
was recognized, and the directions given in Leviticus 
xiv, 42-48, which was probably written about one hun¬ 
dred years before this date, show that the knowledge 
of its antiseptic qualities was widely spread, and the 
practice of it regarded as religious duty. 


10 


CEMENTS AND CONCRETES 


Unfortunately there is no direct evidence that the 
adjacent Assyrian powers of Nineveh and Babylon used 
plaster work. Possibly the fine clay brought down by the 
rivers of the Euphrates and the Tigris sufficed for all 
their purposes. Their records are in it: their illustra¬ 
tions on the sculptured walls of their palaces are in 
stone, their painting is glazed on their bricks, and for 
them there seems to have been but little need for plas¬ 
ter work, nor do we find until the rise of Grecian art 
anything relating to our subject. 

Very early in Greek architecture we find the use of 
plaster, and in this case a true lime stucco of most ex¬ 
quisite composition, thin, fine and white. Some has 
been found at Mycenae, a city of Homeric date. We 
know that it existed in perfection in Greece about five 
hundred years before the Christian era. With this the 
temples were covered externally, and internally where 
they were not built of marble, and in some cases where 
they were. This fine stucco was often used as a ground 
on which to paint their decorative ornament, but not 
infrequently left quite plain in its larger masses, and 
some of it remains in very fair preservation even to 
this day. The Temple of Apollo at Bassae, built of 
yellow sandstone about 470 B. C., has on its columns 
the remains of a fine white stucco. 

Pavements of thick, hard plaster, stained, of various 
colors, wei?§ common in the Greek temples. One of 
these, that of the Temple of Jupiter Panhellenius at 
iEgina, built about 570 B. C., is described by Cockerell 
as existing in the early part of the century, in good 
condition, though the temple itself was destroyed; and 
I have seen at Agrigentum plaster existing in perfect 
state, though scarcely thicker than an egg-shell, on the. 
sheltered parts of a temple built at least three hundred 


INTRODUCTORY 


11 


/ears before our era, whilst the unprotected stone was 
weather worn and decayed. 

What care the ancient Greeks bestowed on their 
stucco may be inferred from Pliny’s statement that in 
the temple at Elis about 450 B. C., Panaenus, the 
nephew of Phidias, used for the groundwork of his 
picture “stucco mixed with milk and saffron, and pol¬ 
ished with spittle rubbed on by the ball of the thumb, 
and,” says he i “it still retains the odor of saffron.” 
Lysippus, the first of the Greek “realists” in sculpture, 
was the first we hear of who took casts of the faces of 
living sitters about 300 B. C., so the art of plaster cast¬ 
ing must have advanced a good deal by that time, as he 
made presents of copies to his friends. Afterwards we 
read of many sculptors who sent smaller plaster models 
of their works to friends. These were, however, prob¬ 
ably carved in the plaster rather than cast. 

Whether the Greeks used stucco for modelling is a 
somewhat doubtful point amongst antiquarians. From 
certain passages in classic writers I am induced to think 
they did. Pausanius, who describes the temple at Stym- 
phalus, an almost deserted and ruined city when he 
visited it about 130 A. D., describes the ceiling of the 
Temple of the Stymphalides, built about 400 B. C., as 
being “either of stucco or carved wood,” he could not 
decide which, but his very doubt would imply that 
stucco or wood were equally common. Now, this ceil¬ 
ing was ornamented with panels and figures of the 
harpies—omens of evil, half woman and half bird, with 
outspread wings. He also mentions a statue of Bac¬ 
chus in “colored stucco.” Of course these are not defi¬ 
nite proofs of early Greek stucco modelling, but as the 
city of Stymphalus had decayed and become depopu¬ 
lated before 200 B. C., there is certainly presumptive 


12 


CEMENTS AND CONCRETES 


evidence of the ancient practice of the art. Again, fig¬ 
ures of unburnt earth are mentioned in contradistinc¬ 
tion to those of terra cotta, and sundry other allusions 
to plastic work occur, which lead me to the opinion that 
quite early in Greek art this mode of using plaster be¬ 
gan. At any rate, we know that it was early introduced 
into Grecia Magna—the earliest Southern Italian col¬ 
ony of the Greeks; and as colonists invariably preserve 
the customs and traditions of their fatherland even long 
after they have fallen into disuse in their native home, 
we can have no reasonable doubt but this art was im¬ 
ported rather than invented by them. Thence it spread 
to the Etruscans of Middle Italy, a cognate people to 
the Southern Greeks, by whom both plain and modelled 
stucco was largely used. The Etruscans, as we have 
seen, were more closely allied to the Greek than the 
Latin race, but in the course of time these two races 
amalgamated, the former bringing skill in handicraft, 
the latter lust of power, and patriotic love of country 
and of glory, whilst the Grecian element, which blended 
harmoniously with the first of these, added a love of art. 

This union, however, took long to ripen to artistic 
fruitfulness. The practical Etruscan element firstly 
constructed the roads and the sewers, and gave health to 
Rome. The Latins added to their territory until it em¬ 
braced half of Europe, giving wealth to Rome, and not 
till the luxury and comfort thus created did the artis¬ 
tic element of the Greek come in, giving beauty to 
Rome, and the day of decorative plaster work ap¬ 
proached its noontide glory, making Rome the attrac¬ 
tion of the world. The absorbance of Greece as a 
Roman province took place B. C. 145, and the loot of 
it began, giving an enormous impetus to Roman art. 
Thousands of statues were brought to Rome, and to 


INTRODUCTORY 


13 


be deemed a connoisseur in things artistic or a patron 
of the arts became the fashionable ajnbition. But it 
was not until the century just preceding the Christian 
era that it became especially noteworthy. Of course 
there is hardly anything left to us of the very early 
plaster work of Rome. The constant search for some 
new thing was inimical to the old. Old structures were 
pulled down to make way for new, which in their turn 
gave way to newer, and until the age of Augustus we 
have but little of the early work left. Strabo, who 
visited Rome about this time, complains of the destruc¬ 
tion caused by the numerous fires, and continued pull¬ 
ing down of houses rendered necessary, for even pull¬ 
ing down and rebuilding in order to gratify the taste 
is but voluntary ruin; and Augustus, who boasted that 
“he found Rome of brick and left it of marble,” in 
replacing the brick with marble destroyed the plaster 
work. How that plaster work was wrought we shall 
learn more from Vitruvius, who wrote his book on archi¬ 
tecture about 16 B. C., and dedicated it to the emperor, 
“in order to explain the rules and limits of art as a 
standard by which to test the merits of the buildings 
he had erected or might erect.” 

Now, Vitruvius was a man who had travelled and 
seen much. He was with Julius Caesar as a military 
engineer in his African campaign in 46 B. C., or ten 
years after Caesar’s invasion of Britain. Afterwards 
he became a designer of military engines, what we 
should call head of the Ordnance Department, and also 
a civil engineer, persuading himself that he had a 
pretty taste in architecture, just as though he were an 
R. E. of today. Thus he had a practical and also an 
artistic training, and here is what he says on matters 
connected with plaster work in Book VII, Chapter 11. 


14 


CEMENTS AND CONCRETES 


On tempering lime for stucco: “This requires that the 
lime should be of the best quality, and tempered a long 
time before it is wanted for use; so that if any of it be 
not burnt enough, the length of time employed in slak¬ 
ing it may bring the whole mass to the same consist¬ 
ency.” He then advises it to be chopped with iron 
hatchets, adding that “if the iron exhibits a glutinous 
substance adhering to it, it indicates the richness of the 
lime, and the thorough slaking of it.” For cradling 
out, and for ceiling joists, he recommends “the wood 
to be of cypress, olive, heart of oak, box and juniper, ’ ’ as 
neither is liable to ‘ ‘ rot or shrink. ’ ’ For lathing he speci¬ 
fies “Greek reeds bruised and tied with cords made from 
Spanish broom,” or if these are not procurable “marsh 
reeds tied with cords.” On these a coat of lime and 
sand is laid, and an additional coat of sand is laid on 
to it. As it sets it is then polished with chalk or marble. 
This for ceilings. For plaster on wall he says: “The 
first coat on the walls is to be laid on as roughly as 
possible, and while drying, the sand and coat spread 
thereon. When this work has dried, a second and a 
third coat is laid on. The sounder the sand and coat is, 
the more durable the work will be. The coat of marble 
dust then follows, and this is to be so prepared that 
when used it does not stick to the trowel. Whilst the 
stucco is drying, another thin coat is to be laid on: this 
is to be well worked and rubbed, then still another, 
finer than the last. Thus with three coats and the 
same number of marble dust coats the walls will be 
solid, and not liable to crack. The wall that is well 
covered with plaster and stucco, when well polished, 
not only shines, but reflects to the spectators the images 
falling on it. The plasterers of the Greeks not only 
make their stucco work hard by adhering to these direc- 


INTRODUCTORY 


15 


tions, but when the plaster is mixed, cause it to he beat¬ 
en with wooden staves by a great number of men, and 
use it after this preparation. Hence some persons cut¬ 
ting slabs of plaster from ancient walls use them for 
tables and mirrors.” (Chapter III.) 

You will see by these remarks the great care taken 
through every process, and how guarded the watchful¬ 
ness over the selection of materials, and you will also 
note the retrospectiveness of Vitruvius’ observation, 
how he felt that the work done before the frantic haste 
of his own time was the better: very much as we find 
now. Time is an ingredient in all good work, and its 
substitute difficult to find. 

There are other “tips” contained in this work which 
are worth extraction, as, for instance, his instructions 
as how to plaster damp walls. In such case he prima¬ 
rily suggests a cavity wall, with ventilation to insure 
a thorough draught, and then plastering it with “pot¬ 
sherd mortar,” or carefully covering the rough plaster 
with pitch, which is then to be “lime whited over,” to 
insure “the second coat of pounded potsherds adhering 
to it,” when it may be finished as already described. 
Further, he refers to modelled plaster work which, he 
says, “ought to be used with a regard to propriety,” 
and gives certain hints for its appropriate use. Speak¬ 
ing of pavements “used in the Grecian winter rooms, 
which are not only economical but useful,” he advises 
“the earth to be excavated about two feet, and a foun¬ 
dation of potsherd well rammed in,” and then a “com¬ 
position of pounded coal lime, sand and ashes is mixed 
up and spread thereover, half foot in thickness, per¬ 
fectly smooth and level. The surface then being rubbed 
with stone, it has the appearance of a black surface,” 
“and the people, though barefoot, do not suffer from 


16 


CEMENTS AND CONCRETES 


cold on this sort of pavement.’’ Now all this bespeaks 
not only theoretical knowledge, but practical observa¬ 
tion and experience, and was written nearly two thou¬ 
sand years ago, from which you can surmise how far 
advanced practical plastering had then become. This 
written evidence is almost all we have of the work of 
Vitruvius’ own time, for even of the time of Augustus 
hardly anything remains to us, as the great fire of 
Nero utterly destroyed the greater part of the city in 
the year A. D. 64, and almost the only authenticated 
piece of plaster work done before or during his reign 
is the Tabula Iliaca, a bas-relief of the Siege of Troy, 
still preserved in the Capitol Museum at Rome. That 
this was modelled by Greek artists is proved by the fact 
that its inscriptions are all in the Greek language, and 
by some it is considered to be of very much greater an¬ 
tiquity. So much for the ancient history of the art 
of plastering, and I trust I will be pardoned if I con¬ 
tinue this sketch, bringing it down to a more recent 
period and show in what high respect the plasterers ’ art 
was held in the Sixteenth Century, and later. Quoting 
from an old work, giving an account of the institution 
of “The Worshipful Company of Plaisterers,” and mak¬ 
ing use of the quaint language then in use we are told 
that: “The Plaisterers’ Company, which ranks as 
forty-sixth among the eighty-nine companies, was in¬ 
corporated by King Henry VII., on March 10, 1501, to 
search, and try, and make, and exercise due search as 
well in, upon, and of all manner of stuff touching and 
concerning the Art and Mystery of Pargettors, com- 
monly called Plaisterers, and upon all work and work¬ 
men m the said art or mystery, so that the said work 
might be just, true, and lawful, without any deceit or 
fraud whatsoever against the City of London or suburbs 


INTRODUCTORY 


17 


thereof. The Charter gave power to establish the Com¬ 
pany as the Guild or Fraternity in honour of the 
Blessed Virgin Mary, of men of the Mystery or Art of 
Pargettors in the City of London, commonly called 
Plaisterers, to be increased and augmented when neces¬ 
sary, and to be-governed by a Master and two War¬ 
dens, to be elected annually. The Master and Wardens 
and brotherhood were to be a body corporate, with per¬ 
petual succession and a common seal, and they were 
empowered to purchase and enjoy in fee and perpet¬ 
uity lands and other possessions in the City, suburbs 
and elsewhere. And the charter empowered the said 
Master and Wardens to sue and be sued as “The Mas¬ 
ter and Wardens of the Guild or Fraternity of the 
Blessed Mary of Pargettors, commonly called Plaister¬ 
ers, London.” 



THE OLD COAT OP ALMS* 


The Company -under the powers to make examina¬ 
tions, appears to have inflicted fines on offending par¬ 
ties for using bad materials, and for bad workmanship. 
Search days appear to have been annually appointed 
up to 1832, but not since, and the Company has not 
exercised any control over Plaisterers’ work for many 
years. 


18 


CEMENTS AND CONCRETES 


Another charter was granted by Queen Elizabeth in 
1559, but it has been lost, and there is no record of 
the contents. The Queen granted a new charter in 
1597, which confirmed the privileges of the Company, 
and extended the authority of the Master and Wardens 
to and over all persons exercising the art of plaisterers, 
as well English as aliens and denizens inhabiting and 
exercising the said art within the City and suburbs and 
liberties, or within two miles of the City. 



THE PRESENT COAT OF ARMS, 


Charles II., by a charter dated June 19, 1679, con¬ 
firmed the privileges granted by the previous charters. 
Having in view the rebuilding of the City, he forbade 
any person to carry on simultaneously the trades of 
a mason, bricklayer or plaisterer, or to exercise or carry 
on the art of a plaisterer without having been appren¬ 
ticed seven years to the mystery. The jurisdiction of 
the Company was extended to three miles’ distance 
from the City. 

There were two orders made by the Court of Aider- 
men (exemplified under the mayoralty seal, April 1) 


INTRODUCTORY 


19 


1585) for settling matters in dispute between the tilers 
and bricklayers and the plaisterers as to interfering in 
each other’s trades. The observance of these orders 
was enforced by an order of the Privy Council dated 
June 1, 1613, and a general writ or precept issue to the 
same effect on August 13, 1613. 



There was also an order of the Court of Aldermen 
(29 Elizabeth, February 14, 1586-7) relating to the 
number of apprentices to be kept by members. 

An act of Common Council was passed, under date 
of 18 James I., October 5, 1620. 

An act of Common Council (6 William and Mary, 
October 19, 1694) was also passed to compel all persons 
using the trade of plaisterer in the City of London or 


20 


CEMENTS AND CONCRETES 


the liberties thereof, to become free of the Company 
under penalty to be recovered as therein mentioned. In 
the East the Art of ornamental plastering was well 
known and almost universally practiced before Mahom¬ 
et established a new order of things, and the enriched 
plaster work of India, Persia and other Eastern Em¬ 
pires are evidences of the high character of the work¬ 
manship of the Oriental workers in plaster. The 
Arabian and Moor brought back the Art of the Western 
World in the early part of the thirteenth century, 
and it is to them we owe the splendid plaster work of 
the Alhambra and other work still in existence in Spain. 
In the Mosque at Medina, built in 622, are still to be 
seen some fine specimens of old plaster work that was 
wrought on the building at the time of its completion. 
The Mosque of Ibu-tubun, Cairo, Egypt, which was fin¬ 
ished in A. D. 878, abounds with beautiful plaster work. 
It contains a number of arches and arcades, the capi¬ 
tals of which, like the rest of the building, are enriched 
with plaster buds and flowers made in elaborate de¬ 
signs. Even in Damascus, thal old and far-off City 
indulged in ornamental plaster-work when the people 
of Western Europe were cutting one another’s throats 
for political ascendency. We illustrate a few examples 
of old work taken from existing specimens. These will 
to some extent, give an idea of what the old plasterers 
could do. See illustrations attached. 

During the middle ages in Europe plastering and 
stucco existed only as a craft, and its highest function 
was to prepare a surface to be painted on. Sometimes 
it was used as an external protection from the weather 
but rarely was it employed for direct ornament. Some¬ 
times small ornaments were carved in plaster of Paris, 
but it played no important part in decorative Art, 


INTRODUCTORY 


21 


excepting perhaps, as gesso, though this belonged rather 
to the painter than the plasterer. Nor was it until the 
commencement of the Renaissance in Italy that it 
showed any symptoms of revival. 



•Arabesque from the Great Mosque. Damascus. 


With the commencement of the fifteenth century old 
learning and old arts began to be studied, the discovery 
of the art of printing and the consequent multiplication 
of the copies of the lore heretofore looked up in old 
manuscripts gave invention and progress new life, 



















































































22 


CEMENTS AND CONCRETES 


'which has lasted until the present day. Italy has al¬ 
ways been the nursing mother of plasterers, and in Mr. 
G T. Robinson’s “Glimpse of the History of the Art 
and Craft,” he has shown something of her great and 
glorious past, and how she sent her sons over almost 
all Europe to raise the art and status of this craft. 



Even during the depressing times of her history she 
religiously preserved its ancient traditions and pro¬ 
cesses, and in almost all her towns there was some one 
or two plasterers to. whom was confided the restoration, 
the repair and the conservation of its frescoes or its 
stuccos. The art dwindled, but it survived. So late 
as 1851 an English architect, when sketching in the 



INTRODUCTORY 


23 


Campo Santo at Pisa, found a plasterer busy in lov¬ 
ingly repairing portions of its old plaster work, which 
time and neglect had treated badly, and to whom he 
applied himself to learn the nature of the lime he used. 
So soft and free from caustic qualities was it that the 
painter could work on it in true fresco painting a few 
days or hours after it was repaired, and the modeller 
used it like clay. But until the very day the architect 
was leaving no definite information could he extract. 
At last, at a farewell dinner, when a bottle of wine 
had softened the way to the old man’s heart, the plas¬ 
terer exclaimed, “And now, signor, I will show you 
my secret!” And immediately rising from the table, 
the two went off into the back streets of the town, when, 
taking a key from his pocket, the old man unlocked a 
door, and the two descended into a large vaulted base¬ 
ment, the remnant of an old palace. There amongst 
the planks and barrows, the architect dimly saw a row 
of large vats or barrels. Going to one of them, the old 
man tapped it with his key; it gave a hollow sound 
until the key nearly reached the bottom. “There, sig¬ 
nor ! there is my grandfather! he is nearly done for. ’ ’ 
Proceeding to the next, he repeated the action, saying: 
‘ ‘ There, signor! there is my father! there is half of him 
left.” The next barrel was nearly full. “That’s me! 
exclaimed he; and at the last barrel he chuckled at 
finding it more than half full: “That’s for the little 
ones, signor!” Astonished at this barely understood 
explanation, the architect learned that it was the cus¬ 
tom of the old plasterers, whose trade descended from 
father to son for many successive generations, to care¬ 
fully preserve any fine white lime produced by burning 
fragments of pure statuary, and to each fill a barrel for 
his successors. This they turned over from time to 


24 


CEMENTS AND CONCRETES 


time, and let it ain—slake in the moist air of the vault, 
and so provide pure old lime for the future by which 
to preserve and repair the old works they venerated. 
After-inquiries showed that this was a common prac- 



Portion of a Ceiling from Teheran, Persia. 


tice in many an old town, and thus the value of old 
air-slaked lime, such as had been written about eighteen 
hundred years before, was preserved as a secret of the 
trade in Italy, whilst the rest of Europe was advocating 










































INTRODUCTORY 


25 


the exclusive use of newly burnt and hot slaked lime. 
Was there in the early part, indeed even in the middle 



PurrKiP Pi aster Panem.ikc. in the Ai.hamhka, Stain, Thirteenth Century. 


of the present century, any plaster image seller who was 
not an Italian? Indeed, at this present time, almost 



26 


CEMENTS AND CONCRETES 


all the “formatore” or piece moulders for the majority 
of the sculptors of Europe are of Italian nationality or 
descent, and chiefly by these has the national craft been 
maintained. 

When after the long European wars of the eighteenth 
and the commencement of the nineteenth century Italy 
had rest and power to “make itself” (faro de se), the 
first revival of its industry was felt by her plasterers, 
and as there was then, as now, more workmen than 



Plaster Frieze in Mosque of Sultan Hasan. Fourteenth Century. 


work, they emigrated to the neighboring countries; and 
the major part of the plasterers along the Revieda, in 
the southern provinces of Germany and Austria, are 
Italians who go off with and return with the swallows, 
to earn that wage the poverty of their own country 
cannot afford them. With this brief historical sum* 
mary I conclude the Introductory notice, and will now 
pass on to the more practical domain of the Plasterers’ 
Art. 
















MATERIALS. 


LIMES, CEMENTS, MORTARS, SAND, PLASTERS AND LATHS. 

LIMES. 

The Lime Principally Used for internal plastering 
is that calcined from carbonate of lime, in which the 
impurities do not exceed 6 per cent., and is known as 
fat lime, pure lime or rich lime. It is unfit for any 
purpose where strength is required, or in situations 
where it is exposed to the weather, as it has no setting 
power, and is easily dissolved by wet. 

Hydraulic Limes are those which, in order to set, do 
not require any outside influences, their own chemical 
composition of lime and silica, when burnt, being suf¬ 
ficient for the purpose. The name is given for their 
capability of setting and hardening under water. Hy¬ 
draulic limes are obtained mostly from the lias. 

Good Hydraulic Limes are obtained from many 
places in the United States and Canada, the best 
known is “The Rosendale Hydraulic Cement.” 

Artificial Hydraulic Limes may be made by mixing 
a sufficient quantity of clay with pure lime to obtain 
a composition like that of a good natural hydraulic 
limestone. The lime, if soft, may be mixed with the 
clay and burnt raw, or, as is more usual, may be burnt, 
slaked, ground, and then mixed with the clay and re¬ 
burnt. 

The Purer the Lime the quicker will it slake. Great 
care should be taken that the lime is properly burnt 
or otherwise it will not slake properly, and will prob¬ 
ably “blow” in the work. 

27 


28 


CEMENTS AND CONCRETES 


The Perfect Slaking of the burnt lime before being 
used is very important as it will slake eventually, and 
cause blisters in the work. In order to effect thorough 
slaking, the lime should be “run” as soon as the build¬ 
ing is commenced. It should not be used unless it has 
been slaked at least three weeks. 

A Bushel of Lime requires in slaking about a gallon 
and a half of water. 

Lime which Slakes Quickly and with great heat is 
generally considered to be the best for plasterers’ work. 

When Lime “Falls” in dry weather without any 
sufficient apparent moisture, it is considered to foretell 
rain. 

The Lime Should Be Run in couch on the site, where 
it can be seen by the architect. Care should be taken 
that as much lime is run as is required for the whole 
of the building. 

The Plasterer, partly, perhaps, to avoid the money 
outlay, and partly to avoid the necessity of having to 
cart away any lime, has a tendency to run an insuf¬ 
ficient quantity of lime. The result of this is that he, 
commencing at the top, the usually less important part 
of the building, has used up his lime by the time he 
has reached the principal rooms on the ground floor, 
and has to have recourse to possibly insufficiently sea¬ 
soned lime, with an unfortunate effect on the work, as 
stated above. 

SAND. 

The Functions of Sand as used in plaster are (1) the 
production of regular shrinkage and the prevention of 
excessive shrinkage, otherwise cracking is the result; 
(2) to form channels for the crystallization. 


MATERIALS 


29 


Sand should be clean, sharp, and hard. The size of 
the grains does not influence the strength of the mortar, 
but, of course, the finer the plaster is required to be 
the finer must the sand be. Fine sand is best for hy¬ 
draulic lime and coarse for fat limes, coarse stuff and 
Portland cement for floating. Uniformity of size is 
not desirable. 

The Proportion of Sand to Lime will vary consider¬ 
ably, according to circumstances, and is difficult to de¬ 
termine. One part of lime to two parts of sand is a 
usual mixture. 

Sand is Cheaper than Lime, and it must be remem¬ 
bered that this is an inducement to use too large a pro¬ 
portion of sand in order to cheapen the plaster. 

Sand is Obtained from rivers, pits, or the sea. Sea 
sand, or that from tidal rivers, should be avoided, as 
the salt never dries, and will come out on the surface 
sooner or later, discoloring the wall papers, paint, etc., 
and keeping the walls damp. 

River Sand is often used, but it is not to be recom¬ 
mended, because the sharpness of the grains is worn 
off by the action of the running water. It is easily 
obtained, however, and the light color of much river 
sand causes it to be used in internal work with the 
white cements. 

Pit Sand is the best. It sometimes contains loam or 
clay, which should be carefully washed out. 

All Sand for High-Class Plastering is best washed. 

HAIR. 

Hair is used in plaster in order to bind it together. 

Good Hair should be long, curled, strong, and clean. 
Ox or cow hair is most generally used, and there are 
three qualities. 


30 


CEMENTS AND CONCRETES 


It Should Be Well Separated before being mixed 
with the plaster, and care should be taken in the mix¬ 
ing that the hairs are not broken. 

CEMENTS. 

Portland Cement, with a large proportion of sand, 
as much as 90 per cent., is useful for internal work; 
it may be used as a backing for a thin floating of the 
white cements. 

The Heavier and Slower in Setting cements are gen¬ 
erally the stronger; but in such plasterer’s work as 
rendering walls the quicker setting cements may be used 
without disadvantage. 

Roman Cement is a “natural” cement. It is liable 
to effloresce on the surface, but is useful where quick 
setting with expansion is required, as in underpinning 
or repairs, without any great ultimate strength. 

Other “Natural Cements” very similar to Roman 
are Medina, Rosendale, Windsor, etc., and are also use¬ 
ful where quick setting is required. 

The TJse of the Natural Cements is much restricted 
at the present time as compared with artificial cements, 
such as Portland. 

Parian Cement is valuable for internal work, by rea¬ 
son of its hardness, nonporosity, and quick setting 
properties. It is hence useful in cases where the walls, 
mouldings, etc., have to stand rough usage. It is also 
washable. This cement will not admit of being re¬ 
worked. 

Keene’s Cement is one of the most useful of the 
artificial cements. It is harder than the other kinds 
made from plaster of Paris, and is much used for pilas¬ 
ters, columns, etc. 2 as it sets quickly and can be pol¬ 
ished, and takes paint excellently. 


MATERIALS 


31 


Martin’s Cement is much the same as Keene’s, and 
used principally for dadoes, etc. In proportion to its 
bulk it covers a large proportion of surface. It can 
be painted, etc., as Keene’s. 

Robinson’s Cement has many advantages, among 
which are its fire-resisting qualities and suitability for 
use on concrete. It is also cheaper than other like 
cements. 

Adamant is another white cement, which is useful for 
work where hardness, facility of application, quick dry¬ 
ing, and a fine surface are required. 

The Above Cements have plaster of Paris (calcined 
gypsum) for their base, and are only adapted for in¬ 
ternal uses, to which they are eminently suited. They 
can all be brought to a good surface, and can be painted 
almost at once. 

Selenitic Cement is based on the property which sul¬ 
phate of lime as plaster of Paris, when added to lime 
possessing hydraulic properties, has of causing its more 
rapid setting. It also increases the proportion of sand 
which it will bear. It is useful in plastering as a hack¬ 
ing for the white cements, such as Parian. 

PLASTER OF PARIS. 

Plaster of Paris is made by the gentle calcination of 
gypsum, previously ground. It is known in the plas¬ 
tering trade as plaster. 

The Principal TJse of Plaster of Paris is in mixing 
with ordinary putty in order to produce greater rapid¬ 
ity in setting, but the fast setting plasters of Paris are 
not, of course, the best for working with, nor do they 
become as hard as the slower setting. 

The Proportion of Plaster of Paris to ordinary lime 
putty varies greatly from about 1 in 4 to 1 in 20, de- 


32 


CEMENTS AND CONCRETES 


pending on circumstances, such as the state of the 
weather, the speed with which the work has to be fin¬ 
ished, etc. It is also used largely for cast ornaments, 
in cornices, etc., and, by reason of its quick setting and 
expansion when setting, for stopping holes, etc. 

LATHS. 

Pine, Cedar and Metal are used for laths for mod¬ 
ern work; only the best quality should be used. 

Oak Laths and Cypress formerly used, are very liable 
to warp. 

The Defects to Be Avoided in Laths are sap, knots, 
crookedness, and undue smoothness. The sap decays; 
the knots weaken the laths; the crookedness interferes 
with the even laying on of the stuff; and the undue 
smoothness does not give sufficient hold for the plaster 
on the lath. 

Liven Laths, split from the log along its fibres, are 
stronger than sawn laths, as in the latter process the 
fibres of the wood are often cut through. 

Laths May Be Obtained in Three Sizes , namely: 
“Single” (average 1-8 in. to 3-16 in. thick), “lath and 
half” (average % in. thick) and “double” (% in. to 
% in. thick). 

The Thicker Laths should be used in the ceilings, be¬ 
cause of the strain upon them, and the thinner in ver¬ 
tical partitions, etc., where there is but little strain. 
Where walls and partitions have to stand rough usage 
the thicker laths are necessary. 

Laths Are Usually Spaced with about % in. between 
them for key. 

A Bunch of Laths usually contains a hundred pieces, 
and such a bunch nailed, with butt joints, coyer a.bqql 


MATERIALS 


33 


4% yds. super., and requires about 500 nails if nailed 
to joists 1 ft. from center to center. 

The Lengths of Laths vary from 3 ft. to 4 ft., the 
latter the usual length. 

Laths Are Best Nailed so as to Break Joint entirely, 
as for various reasons there is a tendency to crack along 
the line of the joints if nailed with the butt ends in a 
row. This may be obviated by using 3 ft. and 4 ft. laths 
together. Ceilings are much stronger if so nailed. 
Laths, however, are usually nailed in bays, about 4 ft. 
or 5 ft. deep. 

Every Lath should be nailed at each end, and wher¬ 
ever it crosses a joist or stud. 

Lap Joints at the end of laths, which are often made 
in order to save nails, should not be allowed as this 
leaves only *4 i n - f° r thickness of plaster. Butt 
joints should always be made. 

Joists, etc., which are thicker than 2 in. should have 
small fillets nailed on their under side or be counter- 
lathed, so that the timber surface of attachment be re¬ 
duced to a minimum and the key be not interfered with. 

Walls which are liable to damp are sometimes bat¬ 
tened or strapped. 

Metal Lathing is now extensively used for its fire¬ 
proof qualities and freedom from rot or harboring of 
vermin. 

Lathing Nails are usually of iron—galvanized, cut, 
wire, or cast; where cak laths are used, the nails 
should be galvanized or wrought. Galvanized nails 
should also be used with white cement work. Zinc 
nails, which are expensive, are used in very good work, 
because of the possibility of the discoloration of the 
plaster by the rusting of iron nails. 


34 


CEMENTS AND CONCRETES 


The Length of Lathing nails depends on the thick¬ 
ness of the laths, % in. long nails being used for shin¬ 
gle laths, 1 in. nails for lath and half laths, and 1% in. 
nails for double laths. 

MEMORANDA. 

One Yard Rendering requires 1-3 cu. ft. lime, *4 cu. 
ft. sand, 2i/ 2 oz. hair, and 1% gal. water. One yard 
render and set requires % cu. ft. lime, % cu. ft. sand, 
3 oz. hair, and 2 gal. water. 

One yard render, 2 coats and set, requires 3-5 cu. ft. 
lime, 2-3 cu. ft. sand, 3 oz. hair, and 2 y 2 gal. water. 

One yard render and float requires % cu. ft. lime, 
% cu. ft. sand, 2 y 2 oz. hair, and 2 y 2 gal. water. 

One yard render, float and set, requires 3-5 cu. ft. 
lime, % ft. sand, 3 y 2 oz. hair, and 2% gal. water. 

Two bushels of gray lime, or 3 of blue lias lime, or 
3 of Roman cement, or 2 of Portland cement, or 14 lbs. 
plaster of Paris, equal one bag. 

1 lb. hair is allowed to 2 cu. ft. of coarse stuff for 
good work, and 3 cu. ft. for common work. 

100 yd. super, of lime whiting, if once done requires 
1 V 2 cu. ft. of lime; and if twice done, 2 cu. ft. of lime. 


WORKMANSHIP. 


EXTERNAL WORK. 

Portland Cement is unquestionably the best material 
for external plastering. For weather resisting proper¬ 
ties, strength, and capacity for moulding and painting, 
it is unequalled. 

The Cement for Rendering requires to be mixed with 
sand in the proportion of about 1 of cement to 4 of 
sand, but for projecting cornices, etc., the proportion 
of sand should be only about half this, as, of course, the 
addition of sand decreases the adhesive power of the 
cement. The fining coat is mixed in the proportions of 
about 2 to 1. 

External Facades in Portland Cement are usually 
laid in two coats; the first coat, known as the rendering 
or floating coat,* is worked to screeds, and is from y 2 
in. to % in. thick. This coat must be carefully cleared 
and well wetted for the second coat, which is known 
as the finishing or fining coat, which is about 3-16 in. 
thick, and is worked with a hand float. 

The Key for External Plastering on brick work may 
be obtained either by building the walls roughly with 
the mortar projecting or by raking the joints at least 
% in. Stone work should be hacked. 

The Surface Must Be Well Wetted , or the wall will 
absorb the water from the rendering coat. 

There is a Tendency to Mix Fat Lime with Portland 
cement in order to make it work more freely, but this 
should not be allowed. 


35 


36 


CEMENTS AND CONCRETES 


Stucco is the term which is loosely applied to all 
kinds of external plastering, whether of lime or cement. 
An enormous amount of “stucco” was done at the end 
of the eighteenth century and the beginning of the 
nineteenth, but is now out of fashion, except for coun¬ 
try and suburban residences. The term is also applied 
to some forms of internal plastering. The principal 
varieties of stucco are common, rough, bastard, and 
trowelled, but cement has largely superseded them. 

Common Stucco was principally employed for ex¬ 
terior work, and was composed of 1 part hydraulic lime 
and 3 parts sand. The surface of the wall should be 
rough and wet as for Portland cement rendering. 

Rough Stucco was used on a floated ground in po¬ 
sitions where it was desired to imitate stone. It was 
worked with a hand float covered with a material such 
as rough cloth, in order to raise the sand and produce 
a stone-like appearance. Cement is now used for the 
same purpose. 

Bastard Stucco and Trowelled Stucco were chiefly 
adapted for painted internal work, and each is laid on 
the second coat as a finish; the first and second coats 
being as for ordinary three-coat work. 

Trowelled Stucco consists of 1 part sand to 2 parts 
fine stuff. It is worked with the hand float till a very 
fine smooth surface is produced. 

Bastard Stucco contains a little hair and has not so 
much labor expended upon it. 

Sgraffito is the name given to ornament which is 
scratched on plaster work. Patterns may be obtained 
by laying differently colored coats (usually two or 
three) on ordinary roughened Portland cement ren¬ 
dering, and removing portions of each coat in the form 
of a pattern. 


WORKMANSHIP 


37 


The Design for the Sgraffito is applied in a cartoon 
and pricked and pounced on the work in the usual way. 
If more colors are required than the coats provide, the 
background may be washed and a combination of 
sgraffito and fresco used. The cutting should be deep 
enough to give a sharp appearance, hut not too deep 
to hold dirt and wet. 

Dough Cast, also known as pebble dashing, is the 
coarsest kind of external plastering. It is very durable 
if properly mixed. Its use in this country dates back 
to very early times. The wall is first plastered, and 
gravel, shingle, or other materials such as spar, broken 
bricks and glass bottles, broken pottery, etc., are thrown 
or dashed at it while it is soft. If the gravel is mixed 
and laid with the plaster there is a tendency in laying 
for it to tear the plaster away from the wall, and as 
the gravel is covered with plaster its appearance is not 
so good. The lime for rough cast should be weather 
resisting, and is generally used hot. 

Depeter is a form of rough cast on which the gravel 
is pressed in by the hand. Ornamental patterns in 
color may be worked in it. Effective but simple deco¬ 
rations for external plaster may be made in various 
ways. Patterns, such as sunflowers, etc., may be in¬ 
cised in it, and a very effective decoration has been 
obtained by merely tapping the plaster with a scratch 
six or seven times alternately in a diaper pattern. In 
half-timber work the plaster is much more pleasing if 
carefully laid with a carelessly unlevel surface, and, of 
course, set back from the timber face about % in. 

INTERNAL WORK. 

Lime Plastering is compounded of lime, sand, hair, 
and water. The proportions of these materials vary 


38 


CEMENTS AND CONCRETES 


according to their nature and the position of the plas¬ 
ter. For successful work good materials and skillful 
mixing are essential. It is applied in one, two, or three 
coats, and by the number of these the plaster is named. 

The Thinner the Coats of plaster are the better, as 
the plaster has a better chance of drying and harden¬ 
ing. 

One-Coat Work, necessarily the commonest 'and 
cheapest, is limited to very inferior buildings, such as 
outhouses and places where it will not be seen, as be¬ 
hind skirtings. One-coat work on laths is specified as 
‘•'lath and lay,” or “lath and plaster,” and on walls 
simply as “render.” 

Two-Coat Work is that usually employed in inferior 
work, such as factories, warehouses, etc., but it is also 
used for the least important rooms in better class build¬ 
ings. Common setting for walls and ceilings is gener¬ 
ally used for this class of work. Two-coat work on 
laths is specified as “lath, lay, and set,” or “lath, plas¬ 
ter, and set,” and on walls as “render, and set.” 

Three-Coat Work is that used in all good buildings, 
and forms a most satisfactory wall finish, when well 
done. Three-coat work on laths is specified as “lath, 
lay, float, and set,” or “lath, plaster, float, and set,” 
and on walls as “render, float, and set.” 

The Processes in Plastering ordinary three-coat work 
are as follows: 

For the First Coat a layer of well-haired coarse stuff 
known as pricking-up is laid to a thickness of about 
y 2 in. This should be laid diagonally and with each 
trowelful overlapping. If on laths it should be soft 
enough to be well worked through them to form a key. 
The surface is then scratched with a lath to form a 
key for the next coat in lines about 4 in. apart. It is 


WORKMANSHIP 


39 


ready for the second coat when too hard to receive an 
impression from ordinary pressure. 

The Coarse Stuff used in the first coat is mortar com¬ 
posed of sand and lime, usually in the proportions of 2 
to 1, with plenty of hair, so that when a trowelful is 
taken up it holds well together and does not drop. 

The Second Coat known as floating, is next laid. 
Four processes. are involved in laying the second coat, 
namely: Running the screeds, filling in the spaces, 
scouring and keying the surface. The scouring is done 
with a hand float, the surface being sprinkled by a 
brush during the process. The keying consists in lining 
the scoured surface with a broom or nail float to form 
an adhesive surface for the finishing coat. 

The Floating is of finer quality than the coarse stuff, 
it does not contain as much hair, and is used in a softer 
state. 

The Third Coat is the finishing coat, and is known 
as the setting coat. Great care must be taken in laying 
this coat in order to obtain uniformity of surface, color, 
smoothness, and hardness. The second coat should be 
uniformly keyed, clean and damp before the third is 
laid. The processes involved are laying, scouring, trow¬ 
elling, and brushing. 

Fine Stuff, which should be used for the finishing 
coat if the walls are to be papered, consists of pure 
lime, slaked and then saturated till semi-fluid, and al¬ 
lowed to stand till the water has evaporated and it 
forms a paste. It may then be thoroughly mixed with 
fine sand in the proportion of 3 parts of sand to 1 part 
of fine stuff. 

Plasterers’ Putty is much like fine stuff, but is care¬ 
fully sieved. 


40 


CEMENTS AND CONCRETES 


Gauged Stuff is plasterers’ putty and plaster of 
Paris in the proportion of three or four to one. If too 
much plaster is used it cracks in setting. It is largely 
used in cornices, and also where the second coat is not 
allowed time to dry, and the work has to be done in a 
hurry. As it sets rapidly, it must be mixed in small 
quantities. 

The White Cements (such as Parian, etc.), of which 
plaster of Paris is the base, are usually laid in two 
coats; the first, of cement and sand, is about y 2 in. to 
% in. thick, and the second of the cement neat. 

Cracks in Plaster Work are caused, apart from the 
natural settlement of the building and the use of in¬ 
ferior materials and workmanship, by the too fast dry¬ 
ing of the work, the laying of the plaster on walls of 
too great suction, by laying one coat on another before 
the lower one has properly set, and by the use of too 
little sand. 

Joist Lines on Ceilings are very unsightly, and are 
caused by the filtration of dust through the intervening 
spaces. They may be prevented by using a good thick¬ 
ness of plaster, and working it well, that it may be hard 
and nonabsorbent and as the dust comes from the top 
and filters through, by protecting the upper side of the 
plaster. 

Pugging consists in laying a quantity of plaster be¬ 
tween the joists of a floor or between the studding of 
a partition* for the purpose of preventing the passage 
of sounds or odors. In the first case, which is the more 
common, the plaster is laid on thin, rough boards fixed 
to battons on the sides of the joists; in the second case, 
which is called “counterlathing” in some parts of the 
country, by plastering on laths nailed between the par¬ 
tition studs. 


WORKMANSHIP 


41 


Pugging Should Not Be Used Too Wet. There are 
three objections to this—the first that it takes a very 
long and inconvenient time in drying; and secondly, 
that the water is liable to be absorbed by the wood, 
and to cause it to rot; and thirdly, it is liable to crack 
in the drying. For this last reason it should always be 
laid in two coats. 

The Buttons should all be nailed at an equal depth 
from the tops of the joists, and the plaster should be 
of an equal thickness throughout, which is obtained by 
drawing a trammel along the joists. 

Mineral Wool is far more sanitary than ordinary 
pugging, has considerable sound and fire resisting qual¬ 
ities, it does not absorb moisture and so rot the laths 
and timbers, is a preventive of vermin, and is light in 
weight. 

Lime Whiting or Whitewash which is lime dissolved 
in water, is a useful and sanitary covering for the 
walls of cellars and outhouses. 

If Lime-Whited Walls Have to Be Plastered, the wall 
should be first carefully picked, as if the lime is left on, 
the plaster is liable to scale. 

Fibrous Plaster is composed of plaster, canvas, wood, 
etc. It is light and dry and can be quickly fixed. 

Ornamental Plaster ceilings may be either modelled 
throughout in situ, or cast in pieces, or formed by work¬ 
ing the ornament on a previously formed flat ceiling. 
The first method is the more costly, but more feeling 
is thereby obtained. 


SPECIFICATION CLAUSES. 


MATERIALS. 

1. The sand for plastering is to be fresh-water river, 
or pit sand, and free from earthy, loamy, or saline 
material, to be well screened, and to be washed if re¬ 
quired. 

2. The laths to be straight-riven or saron pine of the 
strength known as lath and half, well nailed with lin. 
oxidized lath nails, properly spaced for key, and with 
butt-headed joints, double nailed, and breaking joint 
in 3 ft. widths. 

The lathing to be “Expanded metal,” No. — gauge. 

3. The lime for coarse stuff to be approved well- 
burnt grey-stone lime, to be run at least one month 
before being required for use, to be kept clean, and 
well mixed as required with two parts sand and one 
part lime. 

4. The coarse stuff for ceilings, lath partitions, and 
elsewhere where directed to have 1 lb. of good, long 
curled cowhair, free from grease, leading, or other im¬ 
purities, well beaten in, and incorporated with every 
3 cu. ft. of coarse stuff. 

5. Approved lime, free from lumps, flares, or core, 
is to be used for setting, putty, etc., and is to be run 
at least one month before being required for use. 

6. The Portland cement is to be of the best quality 
and description for plastering purposes, from an ap¬ 
proved manufacturer, and must on no account be used 

fresh, but be spread out to cool for at least-weeks 

in a dry shed or room. 


42 


SPECIFICATION CLAUSES 


43 


All suitable cement and all other materials required 
in plastering are to be of the best of their respective 
kinds and descriptions. 

7. Provide all plasterers’ plant, necessary scaffold¬ 
ings, tools, moulds, running rules, straight edges, tem¬ 
plates, etc., of every kind and description necessary for 
the proper execution of the work. 

WORKMANSHIP. 

8. Lath, plaster, float, and set all wood joist ceil¬ 
ings, soffits, and stud partitions, and finish partitions to 
line in trowelled stucco. 

The concrete ceilings and soffits are to be well hacked 
for key and floated and set in gauged stuff, and the 
concrete partitions are to be floated and set. 

Do all dubbing out where required to concrete ceil¬ 
ings, soffits, and partitions in gauged stuff. 

The concrete soffits of strong rooms to be finished 
with one coat of putty gauged with plaster only. 

9. Cover all chases containing pipes, etc., with heavy 
wire lathing suitable for plastering on, securing the 
same in a thorough manner. The wire lathing to be 
wetted in lime water before being put on. 

10. Render, float, and set all walls where not other¬ 
wise described. The walls to .to be finished in 

trowelled stucco. 

11. All cornices and moulded work throughout to 
be run clean and accurately to the sections given. 

All mitres and returns to be truly worked, and all 
enrichments and modelling to be to architect’s ap¬ 
proval, and strictly in accordance with the models and 
instructions given. 

Run moulded plaster cornices .... girt to .... rooms, 



44 


CEMENTS AND CONCRETES 


with all mitres, returned, stopped, and mitred ends, 
etc., as required. 

The cornices to - are to be run in fibrous plas¬ 

ter, fitted and fixed with proper oxidized nails, and 
made good to. 

12. All narrow reveals, splays, and returns to be 
finished in suitable cement on a Portland cement back¬ 
ing. 

Run strong cement angles and arrises on Portland 
cement backing to all projecting angles except the fol¬ 
lowing, which are to be moulded, viz.:. 

Run rounded angles to.of 3 in. girt in strong 

cement as before. 

Run avolo moulded angles 3 in. girt with 2 in. wings 
to .... opening, finished with moulded stops and short 
lengths of angle and arris to detail, all in best cement. 

All exposed surfaces of concrete lintels and girder 
casings are to be finished in white cement internally 
and Portland cement externally, kept flush with faces 
of brickwork; all with arrises and angles excepting 
those otherwise described. 

13. Run Portland cement flush skirting 9 in. high 
to basement, where plastered, with flush head to top and 
trowelled face. 

The skirting to.to be 12 in. high and 1 in. 

projection, sunk and twice moulded in white on Port¬ 
land cement backing. 

Float off the concrete floors of_in Portland ce¬ 

ment to the required level to receive mosaic and the 
pavings. 

14. Run all necessary quirks, spla>s, arrises, etc., 
and make good to all mantelpieces; cut away for and 
make good after all other trades, and cut out and make 





SPECIFICATION CLAUSES 4§ 

good all cracks, blisters, and other defects, and leave 
plaster work perfect at completion. 

15. Ding walls where shown on plans with a coat of 
Portland cement 1 part, sand 2 parts, pea-grit 1 part, 
and ground chalk 1 part. Finish walls where shown 
with a rough coat of Portland cement 1 part and sand 
3 parts, and rough cast with fine pea-grit. 

16. Stop and twice lime white soffits and walls of .. 

17. Twice distemper white all ceilings, soffits, and 
cornices, and twice distemper to approved tints the 
walls of all rooms. 


PREPARATION OF BILL OF QUANTITIES. 


MATERIALS. 

Materials and Plant, etc. —1 to 7. These items ap¬ 
pear in the heading under Specification clauses. 

WORKMANSHIP. 

Ceilings, Partitions, and Walls. —8 and 10. These 
are all billed at per yd. super, including lathing where 
required, also hacking concrete and any dubbing in the 
latter, stating the thickness. Keep all plaster work 
less than 12 in. wide separate in “narrow widths.” 

Wirelathing. —9. These being narrow, it is advisable 
to measure them at per ft. run, stating the width. 

Cornices. —11. Cornices and mouldings under 12 in. 
girt are measured at per ft. run and those over this 
girt at per ft. super, number all mitres, stoppings, etc.; 
those to the running items following same, and those 
to the superficial items averaged for girt. See whether 
bracketing is required; if so, take the girt required at 
per ft. super., numbering angle brackets to mitres and 
returned ends, and averaging the girt. 

Measure the walls and ceilings less by the height and 
projection of the cornice, and add to the girt of the 
cornice 2 in. (i. e., 1 in. for each edge) for the portion 
up to the ceiling and walls. 

Enrichments are measured at per ft. run, giving the 
girt and description, and including the modelling. If 

46 


BILL OF QUANTITIES 


47 


of exceptional character, a provision for modelling is 
sometimes inserted. 

Angles. —12. These appear in bill in feet run with 
the girt of moulding or bead (if any) and also the 
widths of returns. Number the stops, mitres, etc., al¬ 
lowing each to follow the item to which they apply. 

The finishings to concrete beams, lintels, etc., is kept 
separate as in “narrow widths to beams, etc.,” and all 
arrises, etc., being measured at per ft. run. 

Shirtings or Dadoes. —13. Describe skirtings or dadoes 
giving height and projection, and also finish at top, and 
measure at per ft. run, numbering all mitres, ends, etc. 
Include the dubbing with the item. The general wall 
plastering is deducted for these. 

Floating for mosaic and tile pavings appears in the 
bill in yard super. 

Quirks. —14. Labor to splays, quirks, arrises, etc., 
are measured at per ft. run. 

The attendance on trades is frequently measured in 
detail, as “making good around mantels” or gratings, 
etc. 

The cutting-out and making good appears at the end 
of the bill in the form here given. 

Bough Cast. —15. As clauses 8 and 10. 

Lime Whiting and Distempering. —16 and 17. These 
appear in the bill in yd. super. In the case of distem¬ 
pering, if the colors are in any way special mention 
this, and also if in dadoes and filling, taking the di¬ 
viding line in feet run. 

Distempering on cornices is usually measured in ft. 
super., stating the number of tints, and if lines picked 
out in ft. run; as is also distempering on enrichments, 
taking the latter as “extra to,” the distempering to 
cornices being measured over enrichments. 


48 


CEMENTS AND CONCEETES 


LATHS GENERALLY. 

General opinion is undoubtedly in favor of split 
laths, and split laths are sometimes specified by archi¬ 
tects for ceilings and partitions. Sawn laths, unless 
cut from specially selected straight-grained stuff, would 
most assuredly have weak places from uneven grain, 
and in order to avoid this weakness the sawn laths 
would have to be made thicker than split laths, and 
only the best quality should be used. Oak laths, for¬ 
merly used, are very liable to warp. The defects that 
are to be avoided in laths are sap, knots, crookedness, 
and undue smoothness. The sap decays; the knots 
weaken the laths; the crookedness interferes with the 
even laying on of the stuff, and the undue smoothness 
does not give sufficient hold for the plaster on the lath. 
Eiven laths, split from the log along its fibres, are 
stronger than sawn laths, as in the latter process the 
fibres of the wood are often cut through. Sawn laths 
are, however, cheaper than riven laths, and have super¬ 
seded them, which is not desirable in good work. Thick 
laths, because of the strain upon them, should be used 
in the ceilings, and the thinner laths should be used in 
vertical partitions, etc., where the strain is but small. 
Some walls and partitions have to stand rough usage; 
in such cases the thicker laths are necessary. Laths are 
usually spaced with about % in. between them for key. 
A bunch of laths usually contains 360 lin. ft. and such 
a bunch nailed with butt joints, covers about 4 y 2 super, 
yd., and requires about 400 nails if the laths are nailed 
to joists 16 in. from center to center. The length of 
laths varies from 3 ft. to 4 ft. Laths are best nailed so 
as to break joint entirely, because, for various reasons, 
there is a tendency to crack along the line of the joints 


49 


BILL OF QUANTITIES 

if tlie laths are nailed with the butt ends in a row. This 
may be obviated by breaking joints; ceilings are much 
stronger if the laths are nailed in this way. Laths, 
however, are usually nailed in bays, about 4 ft. or 5 ft. 
deep. Every lath should be nailed at each end, and also 
at the place where the lath crosses a joist or stud. Lap 
joints at the end of laths, which are often made' in or¬ 
der to save nails, should not be allowed, as this leaves 
only % i n - for the thickness of plaster. Butt joints 
should always be made. Joists, etc., that are thicker 
than two in., should have small fillets nailed to the un¬ 
der side, or be counter lathed, so that the timber surface 
of attachment may be reduced to a minimum and the 
key not interfered with. 

Lathing nails are usually of iron, and are galvanized, 
cut, wrought, or cast; where oak laths are used, the 
nails should be oxidized or wrought. Oxidized nails 
should also be used with white cement work. Zinc nails, 
which are expensive, are used in very good work, be¬ 
cause of the possibility of the discoloration of the plas¬ 
ter by the rusting of iron nails. The length of lathing 
nails depends on the thickness of the laths, % in. nails 
being used for single laths, and 1% in. nails for double 
laths. 


TOOLS AND APPLIANCES USED BY THE 
PLASTERER. 

The illustrations shown at Figs. 1 and 2 show a num¬ 
ber of tools and appliances made use of by the plas¬ 
terer, and others—special—will be shown further on, 
when it is necessary to describe and illustrate some 
special process or method of working. The tools the 
plasterer requires are many and varied, and may be 
enumerated about as follows: They consist of moulds 
for running cornices, and center moulds, which may 
never be used only in the one piece of work, as the de¬ 
signs and styles of cornices and centers are continually 
changing. As these tools do not cost much, however, 
the changes do not fall heavily on the workman; but it 
is as well, whenever it can be done, to charge each 
mould against its own particular job of work. A good 
spade and shovel will be absolutely necessary to the 
plasterer’s outfit, and will be among the first tools he 
will require. These should be light and strong, and 
well handled, or helved; after using they should have 
all the lime and mortar cleaned off them, and should 
be placed away where they will not be exposed to the 
weather. 

The following list and descriptions of tools will give 
a new beginner an idea of the kind and character of 
tools he will be likely to require before he can success¬ 
fully carry on the plastering business. Most of these 
tools will be illustrated further on: 

The Hoes and Drags .—These are tools so well known 
that they require no description here. They are used 

50 


TOOLS AND APPLIANCES 


51 



NO. 
























































































52 


CEMENTS AND CONCRETES 


chiefly for mixing hair in the mortar, and for loosening 
mortar when too ‘‘stiff,” or when it has developed a 
tendency to “set.” They are also used for preparing 
“putty” and fine “stuff.” (See Fig. 2.) 

The Haivk, which is a square board about thirteen 
inches square, with a short handle on the under side. 
It is used for holding stuff while the operator is at 
work. It is generally made of pine or some other light 
wood; it is made thin on the edges, being beveled from 
the center on the under side to each of the four edges; 
the handle should be about six inches long, and one and 
a half inches in diameter. 

The Mortar-Board is a board similar to a table top, 
and is about forty inches square; it is made by joint¬ 
ing two or more boards together, which are secured by 
two battens, and screws or nails. It is used for holding 
the mortar delivered from the hod direct by the laborer. 

Trowels, which are of two kinds: the ordinary trowel, 
which is formed of light steel four inches. wide and 
about twelve inches long; this is the laying and smooth¬ 
ing tool, and is the most important in a plasterer’s out¬ 
fit. The other is termed a gauging trowel, and is used 
for gauging fine stuff for courses, etc.; it varies in size 
from three to seven inches in length. 

Of Floats, which are used for floating, there are three 
kinds, viz.: the darby, which is not a proper float, is 
single or double, as may be required; the single being 
for one man to use, the double for two. The single one 
should be four feet five inches long, and about four 
inches wide, with a handle near one end, like a hawk 
handle, and a cleat near the other end running length¬ 
wise of the blade; the long darbys have a hawk handle 
on each end. The hard float, which is used in finishing, 
and the quick float, which is used m floating angles. 


TOOLS AND APPLIANCES 


53 



NO. 2. 














































54 


CEMENTS AND CONCRETES 


The hard float is made of good pine, and has a semi¬ 
circular handle on the back; a strip of hard wood is 
sometimes dovetailed into the blade, and the handle is 
screwed fast to the strip previous to the latter being 
driven in the dovetail; this is a good way, as there are 
no nails then driven through the blade, which, by the 
rapid wearing of the latter, would soon project above 
the blade and scratch the plaster where it was intended 
to have it smooth. The quick float is seldom used in 
this country; it is shaped like the angle it is intended 
to work down, and is a trifle handier for this purpose 
than the ordinary hard float. 

Moulds .—These are used for running stucco cornices, 
and are infinite in shape and variety. The reverse of 
the contour of the cornice is cut out of sheet copper or 
iron, and' is firmly attached to a piece of wood which 
is also cut out the reverse shape of the intended mould¬ 
ing. Their uses will be explained under the head of 
Operations. Moulds or matrices for leaves, flowers, or 
other ornaments are made of plaster and glue, or bees¬ 
wax; these will be discussed hereafter. 

Center-Moulds are made on the same principle as the 
reverse moulds for linear cornices, with an arm at¬ 
tached which is perforated at different radii to suit the 
diameter of center-piece. Sometimes the moulds for 
cornicing are so formed, by placing the plates at an an¬ 
gle of forty-five degrees, that they will finish the cor¬ 
nice right into the angle and form the mitre; more fre¬ 
quently, however, the mitres are finished by hand. 

The Pointer is nearly the same shape as a bricklayer’s 
trowel, but it is not so large, being only about four 
inches long. It is chiefly used for small jobbing, or 
mending broken or defective tfrork. 


TOOLS AND APPLIANCES 


55 


The Paddle is simply a piece of pine wood less than 
three inches wide and six long, by one thick; it is made 
wedge shaped on one end, the other end being rounded 
off for a handle. Its use is to carry stuff into angles 
when finishing. 

Slopping and Picking-Out Tools, or, as they are fre¬ 
quently called, Mitering Tools, are made of fine steel 
plate, seven or eight inches long, and of various widths 
and shapes. They are used for modeling, and for fin¬ 
ishing mitres and returns to cornices by hand where the 
moulds cannot work. 

Mitering-Rod. —This is a tool one foot or more long, 
and about one-eighth of an inch thick, and three inches 
wide; the longest edge is sharp, and one end is bev¬ 
elled off to about thirty degrees. It is used for clean¬ 
ing out quirks in mouldings, angles, and cornices. 

The Operator also requires a good whitewashing 
brush with a short handle. The best should be ob¬ 
tained, as it will prove the cheapest in the end. 

A Scratcher is generally made of short pieces of pine 
two inches wide and one inch thick; three or four of 
them are nailed to two cleats, and are placed about an 
inch apart. The center slat should be about eighteen 
inches longer than the others, so as to form a handle. 1 
See illustrations. The slats on the opposite end to the 
handle should be cut off square with one side and point¬ 
ed. Its use is to make grooves, or bond in what is called 
the scratch coat. When completed it has somewhat the 
appearance of a gridiron. 

Hod. —This is formed by two boards, eleven and 
twelve inches wide, respectively, and eighteen inches 
long, the wide board being nailed on the edge of the 
narrow one, making a right-angled trough; one end is 
closed, and the end piece is rounded over the top; the 


56 


CEMENTS AND CONCRETES 


boards forming the sides are rounded at the opening. 
A handle about four feet long and two inches in diam¬ 
eter is then fastened about two inches forward of the 
middle nearer to the open end, and a piece of wood 
called a pad is fitted with a groove on the angle just 
back of the handle. The object of this block is to pre¬ 
vent the arris of the hod from chafing the shoulder of 
the laborer. Much controversy has taken place among 
workmen at various times regarding the exact size of 
hod, but this, I think, should be governed more by the 
strength of the person who has to use the particular 
hod than by any fixed rules. Hods for carrying mortar 
need not be so large as hods intended for carrying 
bricks. (See No. 2, Fig. 1.) 

Sieve .—This is used for straining through putty for 
finishing; it requires to be very fine for the purpose. 
Sometimes a hair sieve is used, but they are not last¬ 
ing, and should never be used when a wire sieve is ob¬ 
tainable. Sometimes a hair sieve may prove convenient 
where dry plaster or cements have to be run through a 
sieve of some kind before it can be used; so, on the 
whole, the plasterer who desires a full and complete 
outfit, should provide himself with one good hair sieve, 
and at least two sieves of wire. (See Fig. 7, No. 1.) 

Sand Screens are usually twenty-one inches wide in¬ 
side by about six feet long. On small work they are 
stood up at an angle of forty-five or more degrees, and 
the sand is shovelled against them; in some large works 
the- screen is suspended, and one man shovels in the 
sand and a second one swings or shakes the screen. 
These screens, to be lasting, should have their sides and 
ends made of sheet iron, and the bottom should be 
formed with parallel rods of small round iron having 
wires running across them at regular intervals. These 


TOOLS AND APPLIANCES 


57 


cross wires should be attached to the? iron rods so as to 
hold them in place. The parallel rods may be placed 
at such distances from each other as will he most con¬ 
venient for the work in hand. 

Mortar Beds are made of rough lumber of any kind, 
and should be built partly in the ground, where cir¬ 
cumstances will permit. They require to be strongly 
put together, as they have considerable weight to sus¬ 
tain. The writer has seen mortar beds built up with 
bricks and cement where large works have been under 
construction. Sometimes, master workmen, who do a 
large business, and who employ a great number of men, 
keep a large mortar bed or two in the rear yard of 
their shop and tool house, in which they keep always 
cn hand a supply of ready-made stuff, which enables 
them to do small jobs or repairs at a moment’s notice. 

The Slack Box .—This is generally made of boards, 
and is eight or nine feet long, and from two to four 
feet wide, and twelve or sixteen inches in depth. An 
opening about eight inches square is left in one end, 
with a slide door attached, so that it can be opened or 
closed at pleasure. The opening should be covered on 
the inside with a grating, so that when the lime is run 
off no lumps or stones will get through. The grating 
may be made with iron rods, or may be formed with 
wooden laths or slats. The bottom of the box should 
be made as close and tight as rough boards will permit. 
(See No. 1, Fig. 11.) 

Lathing. t—It frequently happens in towns and coun¬ 
try places that the plasterer has to do his own lathing, 
or at least have it done under his own supervision, 
therefore it will be necessary to have something to say 
on this subject, and on the tools employed by the work¬ 
man whose duty it is to prepare the walls for the plas- 


58 


CEMENTS AND CONCRETES 


terer. These tools need not be extravagant ones or 
many in number. They consist of the following: 

Lather’s Hatchet .—This is a small hatchet with a 
blade not more than one and a half inches wide, and 
rather larger in proportion than ordinary hatchets. 
The opposite end to the cutting edge is a hammer, with 
which the lather drives the nails. Sometimes the face 
of the hammer end is grooved, which makes it cling to 
the nails if the latter are not struck fairly on the head. 
An expert lather, however, will prefer a flat hammer 
face for driving lath nails. The cutting edge is used 
for “nipping” off laths when they are too long, or 
when short spaces of lathing are required to be made. 
In cutting lath with the hatchet, the workman gives the 
wood a short sharp blow with the tool at the point 
where the severance is required, and the lath is in¬ 
variably cut at the first blow, if the operator is an ex¬ 
pert. (See 0, Fig. 2.) 

Nail Pocket .—Perhaps the best nail pocket a lather 
can have is made from a portion of an old boot leg cut 
off to about four inches deep, and having a bottom of 
semi-circular shape made of wood, and to which the 
portion of the boot is fastened by means of broad-head¬ 
ed tacks. The pocket is fastened to the workman’s 
waist by means of a strap, or other suitable device, and 
hangs in front of him in a convenient position. Some¬ 
times nail pockets are made of canvas, but these are 
not so handy, as the top is apt to close and then nails 
are difficult to get at. This never occurs with the boot 
leg pocket. 

Cut-off Saw.—A cross-cut saw is an indispensable 
tool to the lather for cutting lath in larger quantities 
for short spaces, and for rigging up platforms to work 
on, and for cutting supplementary studding or strips 


TOOLS AND APPLIANCES 


59 


where such are necessary. The saw should have rather 
coarse teeth and have plenty of set. Usually, the lather 
thinks that almost any old used-up saw is good enough 
for this purpose, and we find him struggling away with 
all his strength cutting through a bundle of lath, when, 
if he had a saw that was worth anything—as a saw— 
he would perform his labors with about one-half the 
effort, and one-third of the time. It is all wrong to 
think of being able to work satisfactorily with inferior 
or imperfect tools. There is no economy in using tools 
of this kind, and any lather who fancies he is going 
to make or save anything by making use of an old 
buckled, mortar-stained saw, makes a terrible mistake. 
Get a good saw and keep it in good order, and it will 
pay you in two weeks. (See X, Fig. 2.) Besides these 
enumerated, there are many other tools and appliances 
that the plasterer will require, such as jointing rules, 
moulding knives, modelling tools, drags, chisels, com¬ 
passes, plumb rules, etc. 


PLASTER, LIME, CEMENTS, SAND, ETC. 

Plaster of Paris. —Gypsum, from which plaster of 
Paris is made, is a sulphate of lime, and is so named 
from two Greek words;—ge, the earth; and epsun, to 
concoct, i. e., concocted in the earth. In Italy it is 
known by the name of gesso; in Scotland it is called 
stucco; in this country it is known as calcined plaster; 
and in the English trade as plaster. The term “plas¬ 
ter” will henceforth be used in this book. The writings 
of Theophrastus and other Greek authors prove that 
the use of plaster was known to them. A stone, called 
by Theophrastus gypsos, chiefly obtained from Syria, 
was used by the ancients for converting into plaster. 
Gypsum is mentioned by Pliny as having been used by 
the ancient artists, and Strabo states that the walls of 
Tyre were set in gypsum. The Greeks distinguished 
two kinds—the pulverulent and the compact. The lat¬ 
ter was obtained in lumps, which were burnt in the fur¬ 
naces, and then reduced to plaster, which was used for 
buildings and making casts. 

Gypsum is found in most countries—Italy, Switzer¬ 
land, France, Sicily, The United States, and some of 
the South American States; also in Newfoundland and 
Canada. The latter is said to be the finest deposits in 
the world. It is found in England in many places. 
The finest gypsum is called “alabaster,” and is soft, 
pure in color, and fragile. This white translucent ma¬ 
terial is a compact mass of crystalline grains, and is used 
for making small statuary, vases, and other ornaments 
Gypsum is found in immense quantities in the tertiary 

60 


PLASTER, LIME, ETC. 


61 


strata of Montmartre, near Paris. This gypsum usual¬ 
ly contains 10 per cent, of carbonate of calcium, not al¬ 
ways in intimate union with the sulphate, but inter¬ 
spersed in grains. This sulphate gives the Paris plas¬ 
ter some of its most useful properties. Pantin, near 
Paris, has large beds of gypsum, one bed being hori¬ 
zontal and over 37 ft. thick. 

The term “plaster of Paris” was mainly applied to 
it because gypsum is found in large quantities in the 
tertiary deposits of the Paris basin. Another reason 
is that lime and hair mortar is seldom used in Paris for 
plaster work, plaster of Paris being used for most kinds 
of internal and external work. Plaster is known in the 
color trade as terra alba. Plaster of Paris was known 
in England by the same name as early as the beginning 
of the thirteenth century. The gypsum, in blocks, was 
taken from France, and burnt and ground there. It 
continued to be burnt and ground by the users until 
the middle of the nineteenth century. The burning 
was done in small ovens, and the grinding in a mill, 
sometimes worked by horse-power, or more often by 
hand. 

Plaster is the most vigorous as it is the oldest vehicle 
for carrying down generation after generation the mas¬ 
terpieces of art with which the golden age of sculpture 
enriched the human race. For reproductive uses, plas¬ 
ter enables youth to contemplate antiquity in its noblest 
achievements. Today plaster is revolutionizing indus¬ 
trial art for us, and in all probability for those who 
are to come after us. Plaster, lowly and cheap, but 
docile and durable, is the connecting agent with this 
greatest of men’s endorsement in the past. Plaster 
thus employed in duplicating works of marble, pottery, 
and metal work, is today extending the finest indus- 


62 


CEMENTS AND CONCRETES 


tries, modern and ancient. Plaster is one of the best 
known fire-resisting materials for building purposes. 
After the conflagration at Paris, it was found the beams 
and columns of wood which had been plastered were 
entirely protected from fire. In cases where limestone 
walls had been ruined on the outside by the flames pass¬ 
ing through the window openings, the same walls in¬ 
ternally escaped almost unscathed owing to their being 
protected with plaster. Plaster in some climates has 
great lasting properties. The Egyptians covered their 
granite sometimes, and sand stone always, with a thin 
coating of stucco. The Greeks coated even their mar¬ 
ble temples with plaster, and the plaster portions are 
now in better preservation than unprotected masonry, 
particularly at Agrigentum in Sicily. 

Quick and Slow Setting Plaster. —M. Landrin, in giv¬ 
ing the results of his long continued studies relative 
to the different qualities of gypsum, states that the 
more or less rapid setting of plaster is due to the mode 
in which it is burned. Its properties are very different 
when prepared in lumps or in powder. The former 
when mixed in its own weight of water sets in five min¬ 
utes, while the latter under similar conditions takes fif¬ 
teen minutes. The reason probably is that- plaster in 
powder is more uniformly burned than when it is in 
lumps, which tends to prove this fact, that when, the 
latter is exposed longer than usual to the action of heat 
it sets more slowly. Gypsum prepared at a high tem¬ 
perature loses more and more of its affinity for water, 
retaining, however, its property of absorbing its water 
of crystallization. Plaster heated to redness and mixed 
in the ordinary manner will no longer set; but if, in¬ 
stead of applying a large quantity of water, the small¬ 
est possible portion is used (say one-third of its 


PLASTER, LIME, ETC. 


63 


weight), it will set in ten or twelve hours, and becomes 
extremely hard. To prepare good plaster, it should not 
be burned too quick to drive off all its moisture, and 
for its molecules to lose a part of their affinity for the 
water. If the plaster is exposed to heat until it has 
only lost 7 or 8 per cent, of its moisture it is useless, 
as it sets almost immediately. If, however, the burning 
is again resumed, the substance soon loses its moisture, 
and if then exposed to the air it very rapidly retakes 
its water of crystallization, and absorption continues 
more slowly. It then sets slowly, but attains great 
hardness. 

Testing .—The quality of plaster may be tested by 
simply squeezing it with the hand. If it cohere slight¬ 
ly, and keeps in position after the hand has been gently 
opened, it is good; but if it falls to pieces immediately 
it has been injured by damp. Although plaster does 
not chemically combine with more than one-fourth of 
its weight of water, yet it is capable of forming a much 
larger quantity into a solid mass, the particles of plas¬ 
ter being converted into a network of crystals, mechan¬ 
ically enclosing the remainder of the water. Sulphate 
of lime (plaster) is soluble in water to the extent of 1 
part in about 450, the solubility being but little influ¬ 
enced by temperature. It is on account of this solu¬ 
bility in water that cements which have to a large ex^ 
tent plaster for their bases are incapable in this raw 
state of bearing exposure to the weather. The setting 
of plaster is due to hydration, or its having but little 
water to take up to resume a state of consolidation. 
Plaster is used with hydraulic limes to stop the slaking, 
and convert the lime into cement. These are then called 
“selenitic.” 

In 100 parts of gypsum there are 46 acid, lime 32, 


64 


CEMENTS AND CONCRETES 


and water 22 parts. Good plaster should not begin to 
set too soon, and it should remain for a considerable 
time in a creamy state. When once set it should be 
very hard. Plaster should set slowly, as it gives more 
time for manipulation, but principally because one 
which sets quickly and swells never becomes so hard 
as slow-setting material. The quality of plaster can¬ 
not be determined by its color, the color being regu¬ 
lated by that of the gypsum; but all things being equal, 
the whitest and hardest generally yields the best plas¬ 
ter. But as the exception proves the rule, it may be 
mentioned that some plasters (such as Howe’s) are of 
a delicate pink tint, and of a very fine grain, and ex¬ 
ceedingly strong when gauged. This pink plaster is 
much appreciated by many plasterers for making origi¬ 
nals, as owing to its fineness and density it is very suit¬ 
able for cleaning or chasing up models taken from the 
clay, and also for durable moulding pieces. One of the 
whitest plasters known, which is also very close in tex¬ 
ture, is that manufactured by Cafferata. For cast work 
the color of plaster is of small moment, because the cast 
work is sooner or later colored with paint, and more¬ 
over, unfortunately daubed over with distemper, or 
worse still, with whitewash. Coarse plasters are darker 
in color than fine. Coarse plasters of a sandy nature, 
and which rapidly sink to the bottom when put in 
water, contain too much silica, or improperly burnt 
gypsum, or are derived from a bastard gypsum, and 
are generally of a weak nature. 

Compressive and Adhesive Strength .—The compres¬ 
sive resistance of properly baked plaster is about 120 
lbs. to the square inch when gauged with neat water 
and 160 lbs. when gauged with lime water; thus show¬ 
ing that lime water hardens and improves the affinity 


PLASTER, LIME, ETC. 


65 


of plaster. The adherence of plaster to itself is greater 
than to stone or brick. The adhesion to iron is from 
24 to 37 lbs. the square inch. 

French Piaster .—A considerable quantity of French 
plaster was formerly used in this country but our own 
is more uniform in quality and cheaper in price, so the 
use of the French material is somewhat limited. In 
Paris various kinds of gypsum mortars are in general 
use, raw gypsum and other materials being often inter¬ 
mixed. They also contain free carbonate of lime, ac¬ 
cording to the degree of heat to which the raw stone 
has been subjected. The Hotel de Platres, in Paris, 
affords a good illustration of the constructive uses to 
which plaster can be put, some of the blocks being 
about a hundred years old. 

Limes .—Lime is one of the most important materials 
in the building trades. Limestone is the general term 
by which all rocks are roughly classified which have 
carbonate of lime for their basis. They are obtained 
from many geolcgical formations, varying in quality 
and chemical properties. The carboniferous consists 
of nearly pure carbonate of lime. In the limestone of 
the lias carbonate of lime is associated with silica and 
alumina (common clay), in proportions varying from 
10 to 20 per cent. Carbonate of lime is found in a state 
of chemical purity in rhombohedral crystals as Iceland 
spar. It is also found in six-sided prisms, known to 
mineralogists as arragonite. Its purest form as a rock 
is that of white marble. Colored marbles contain iron, 
manganese, etc. 

The lias strata consists of a thin layer of hard lime¬ 
stone separated by another of a more argillaceous char¬ 
acter, or shale, containing various proportions of car¬ 
bonate of lime. 


66 


CEMENTS AND CONCRETES 


Hydraulic Limes .—Hydraulic limes are those which 
have the property of setting under water or in damp 
places, where they increase in hardness and insolubil¬ 
ity. The blue lias lime formation is that from which 
hydraulic lime is principally made. This lime, while it 
has excellent hydraulic properties, can hardly be classed 
as a cement. The stones which produce these limes con¬ 
tain carbonate of lime, clay, and carbonate of mag¬ 
nesia. The clay plays an important part in giving hy- 
draulicity to the lime, consequently this power is great¬ 
er in proportion to the amount of clay contained in the 
lime. The proportion of clay varies from 10 to 30 per 
cent. When lime contains clay it is not so easily slaked 
as pure lime, and does not expand so much in doing 
so, and therefore does not shrink so much in setting. 

Lias lime (called blue lias from the color of the stone 
from which it is produced) is very variable in quality 
and is generally of a feeble nature, but is sometimes of 
an hydraulic nature. M. Yicat divides them into three 
classes: feebly hydraulic, ordinary hydraulic, and emi¬ 
nently hydraulic. “ Those belonging to the first class 
contain from 5 to 12 per cent, of clay. The slaking 
action is accompanied by cracking and heat. They also 
expand considerably, and greatly resemble the fat limes 
during this process. They are generally of a buff color. 
Those of the second class contain from 15 to 20 per 
cent, of clay. They slake very sluggishly in an hour 
or so without much cracking or heat, and expand very 
little. They set firmly in a week. The eminently hy¬ 
draulic limes contain from 20 to 30 per cent, of clay, 
are very difficult to slake, and only do so after a long 
time. Very frequently they do not slake at all, being 
reduced to a powder by grinding. They set firmly in 
a few hours, and are very hard in a month.” 


PLASTER, LIME, ETC. 


61 


A natural hydraulic lime is obtained from what ap¬ 
pears to be a sedimentary limestone that has been 
formed by being deposited from water which held it in 
solution. It is very fine-grained, and contains almost 
no fossils, and scarcely the trace of a shell is to be seen, 
except at the top and bottoms of the divisions, which 
are four in number, and in all from 9 to 12 ft. thick. 
When first worked, the stone was slaked in hot kilns; 
but now this is effected by grinding. According to the 
* ‘M’ Ara 9 ’ process, the ‘‘lime shells” from the kiln are 
ground in the same way as the clinker of Portland ce¬ 
ment. Beginning with a stone-breaker, the lime passes 
from this to a pair of chilled crushing rollers, and final¬ 
ly to the millstones, after which the powder is carried 
by sere v-conveyor and elevator to a rotary screen, 12 ft. 
by 4 feet, covered with wire cloth, which retains and 
returns to the millstones any residue in excess of the 
required fineness. Sifting is a very important factor in 
the process, as it is scarcely possible to have the mill¬ 
stones so perfect that they will not pass a few large 
particles. 

The residue of imperfectly ground lime will doubt¬ 
less slake when mixed with water, but at long or un¬ 
certain periods, so that it is obvious that fine grinding 
is a necessity, and the setting properties are not fully 
and safely developed unless the whole is finely pulver¬ 
ized. With regard to “Fat lime”: the general prac¬ 
tice is for lime producers to show their lime as rich as 
possible by analysis, and for users to prefer a rich lime, 
for the reason that it makes a more plastic and better 
working mortar with the usual quantity of sand. Now, 
it has been proved by experiments, many and varied, 
and extending over a long period, by the most eminent 
authorities, French, German, English and American, 


68 


CEMENTS AND CONCRETES 


that this preference should exactly be reversed, and 
that the poorer common limes will make the best mor¬ 
tar, and will, in a comparatively short time, show some 
light setting power, whereas the very rich limes never 
take band, except in so far as they return to their orig¬ 
inal condition of carbonate by the reabsorption of car¬ 
bonic acid from the atmosphere, and by the slow evap¬ 
oration of the water of mixture. If it does not evapo¬ 
rate, the mortar remains always soft. If it evaporates 
too quickly, the mortar falls to powder, a result which 
must be in every one’s experience who has witnessed 
the taking down of old buildings, and the clouds of 
dust created by the removal of every stone. 

Some of the stones from which fat lime is produced 
contain a portion of sand as an impurity. They there¬ 
fore yield an inferior substance. This, though cheaper, 
is not so economical as pure lime, as it does not increase 
its volume so much when slaked. The pure or fat lime 
should only be used for plastering, as it is easily slaked, 
and therefore not so liable to blister as most hydraulic 
limes. It expands to double its bulk when slaked, and 
can be left and reworked again and again without in¬ 
juring it. 

The Romans are said to have prepared their limes. 
This ‘dime putty,” prepared by immersion for a longer 
or shorter period—seldom less than three weeks—before 
being used, is laid on in a very thin coat, and gives 
a hard skin to the surface. This hardness is largely, if 
not wholly, due to the fact that the lime is laid on in 
a thin layer on the floating coat that has already ab¬ 
sorbed carbonic acid from the air. This thin layer be¬ 
comes harder than the main body of the plaster. . 

The whole process of preparing lime and laying 'J 
on the walls in thin coats, with a considerable space 01 


PLASTER, LIME, ETC. 


69 


time between the coating, is conducive to the ultimate 
hardness of the whole. The lime is first slaked, and 
then made into coarse stuff, and setting stuff, all this 
t : me being exposed to the carbonic acid of the atmos¬ 
phere. Again, each coat is long exposed to the same 
influence before being covered with the next, although 
in marked contrast to the system of using the mortar 
in building. 

Calcination .—The process of “lime burning” is car¬ 
ried out in several different ways. But whether the 
operation be carried out in the simplest manner, or in 
kilns constructed on the most scientific principles, it 
will still depend (both as regards the quality and quan¬ 
tity of lime produced) upon the kilnsman, as it is only 
by constant observation from day to day that the man 
becomes capable of judging whether the proper tem¬ 
perature has been reached or that a correct opinion 
can be formed as to the effects produced by the various 
disturbing causes which exert an important influence 
upon the working of a kiln, such as its size, shape, the 
quality of the fuel, and the state of the atmosphere. 
The kilns vary in size and shape in different districts, 
though they are generally inverted cones or ellipsoids, 
into which layers of limestone and fuel are alternately 
thrown. When worked continuously as running kilns, 
the lime is periodically withdrawn from below, fresh 
quantities of fuel and stone being filled in at the top. 
When lime has not been properly calcined, or “dead 
burnt,” it will not slake with water. This may arise 
from two causes—from insufficient burning, when the 
limestone, instead of being entirely caustified, has only 
been changed into a basic carbonate, consisting of two 
equivalents of lime and one of carbonic acid, one-half 
only of its carbonic acid having been expelled. This 


70 


CEMENTS AND CONCRETES 


basic carbonate, on the addition of water, instead of 
forming a hydrate of lime, and being converted into 
a fine and impalpable powder, attended with the pro¬ 
duction of a large amount of heat, is changed, with 
little elevation of temperature, into a mixture of hy¬ 
drate and carbonate. In the case of hydraulic limes 
which contain a considerable amount of silica, this 
“dead burning” may arise from the limestone having 
been subjected to a too high temperature, whereby a 
partial fusion of the silicate of lime formed has been 
produced, giving an impervious coating to the inner 
portions of the stone, retarding the further evolution 
of the carbonic acid. On this account the eminently 
hydraulic limes require to be carefully calcined at as 
low a temperature as practicable; and hence it is not 
infrequently found that lias lime has been imperfectly 
calcined. Pure limes, if subjected to an excessive 
temperature, exhibit somewhat less tendency to com¬ 
bine with water than is the case with lime properly 
calcined. Caustic limes unite with water with great 
energy, so much so as to evolve a very considerable 
amount of heat. When water is poured upon a piece 
of well-burnt lime heat is rapidly generated, and the 
lime breaks up with a hissing, crackling noise, the 
whole mass being converted in a short time into a soft, 
impalpable powder, known as “slaked lime.” 

Slaking .—Chemically speaking slaked lime is hydrate 
of lime—that is, lime chemically combined with a 
definite amount of water. In the process termed “slak¬ 
ing” one equivalent or combining proportion of lime 
unites with one equivalent of water, or in actual weight 
28 lbs. of lime combines with 91 lbs. of water (being 
nearly in the proportion of three to one) to form 37 
lbs. of solid hydrate of lime. The water loses its liquid 


PLASTER, LIME, ETC. 


71 


condition, and it is to this solidification of water that 
the heat developed during the process of slaking is 
partly due. 

Slaking is a most important part in the process of 
making coarse stuff and putty lime. Unless the slak¬ 
ing is carefully and thoroughly done, the resultant ma¬ 
terials are liable to ‘ 4 blister’ 7 or “blow,” owing to 
small particles still remaining in a caustic state. Blis¬ 
ters may not show until a considerable time has 
elapsed. There are three methods of slaking “lump- 
lime”—the first by immersion; the second by sprink¬ 
ling with water; and the third by allowing the lime to 
slake by absorbing the moisture of the atmosphere. 
Rich limes are capable of being slaked by immersion, 
and kept in a plastic state. They gain in strength by 
being kept under cover or water. Pliny states that the 
Romans had such great faith in this method that the 
ancient laws forbade the use of lime unless it had been 
kept for three years. All rich limes may be slaked 
by mixing with a sufficient quantity of water, so as to 
reduce the whole to a thick paste. Lump lime should 
first be broken into small pieces, placed in layers of 
about six inches thick, and uniformly sprinkled with 
water through a pipe having a rose on one end, or by 
means of a large watering-can having also a rose, and 
covered quickly with sand. It should be left in this 
state for at least twenty-four hours before being turned 
over and passed through a riddle. The layer of sand 
retains the heat developed, and enables the process of 
slaking to be carried out slowly throughout the mass. 
Any unslaked lumps may be put into the middle of the 
next heap to be slaked. The quantity of water should 
be perfectly regulated, as if over-watered a useless paste 
is formed. If a sufficient quantity is not supplied, a 


72 


CEMENTS AND CONCRETES 


dangerous powdering lime is produced. Slaking by 
sprinkling and covering the lime lumps is frequently 
done in a very imperfect and partial manner, and por¬ 
tions of the lime continue to slake long after the mortar 
has been used. Special care must be exercised, and 
sufficient time must be allowed for the lime to slake 
when this method is employed. 

Different qualities of lime require variable amounts 
of water; but the medium quantity is about a gallon 
and a half to every bushel of lime. No water should 
be added or the mass disturbed after slaking has be¬ 
gun. In most places the lime for making coarse stuff 
is generally slaked by immersion, and is run into 
a pit, the sides of which are usually made up with 
boards, brick work, or sand, the lime being put into 
a large tub containing water. When the lime is slaked, 
it is lifted out by means of a pail, and poured through 
a coarse sieve. It is sometimes made in a large oblong 
box, having a movable or sliding grating at one end to 
allow-the lime to run out and also to prevent the sedi¬ 
ment from passing through. 

In preparing lime for plaster work, the general prac¬ 
tice is to slake it for three weeks before using. Not 
only so, but a particular cool lime is selected, for the 
reason that it is not liable to blister and deface the 
internal walls when finished. Now, while all this pre¬ 
caution is taken in regard to plastering, in making mor¬ 
tar for building the lime is slaked and made up at 
once, and it is frequently used within a day or two. 
But this is not all. Limes which are unsuitable for 
plaster work, known as hot limes, and which, when 
plasterers are obliged to use 2 must be slaked for a 
period of—not three weeks, but more—nearly three 
months before using, and are then not quite safe from 


PLASTER, LIME, ETC. 


73 


blistering, are the limes mostly used for building pur¬ 
poses. It will at once be seen that when mortars of 
these limes are used immediately, the unslaked par¬ 
ticles go on slaking for a long time, drying up the 
moisture, and leaving only a friable dust in the joints. 
This should help in understanding the old Roman law 
which enacted that lime should be slaked for three 
years before using. If three years should seem to us 
an absurd time, yet it may be justly said that at least 
three months are required to slake completely, and to 
develop fully the qualities of many of the common 
limes in everyday use. Major-General Gillmore, the 
eminent American specialist on the subject of Limes 
and Cement, mentions that in the south of Europe it 
is the custom to slake the lime the season before it is 
to be used. 

Mortar .—This is a term used for various admixtures 
of lime or cement, with or without sand. For plaster 
work it is usually composed of slaked lime, mixed with 
sand and hair, and is termed “coarse stuff,” and some¬ 
times “lime and hair,” also “lime.” In Scotland the 
coarse stuff is generally obtained by slaking the lump 
lime (locally termed shells) with a combination of 
water sprinkling and absorption. The lime is placed in 
a ring of sand, in the proportion of one of lime to 
three of sand, and water is then thrown on in suffi¬ 
cient quantities to slake the greater portion. The whole 
is then covered up with the sand, and allowed to stand 
for a day; then turned over, and allowed to stand foi 
another day; afterwards it is put through a riddle to 
free it from lumps, and allowed to stand for six weeks 
(sometimes more) to further slake by absorption. It 
is next “ soured ”—that is, mixed with hair ready for 
use. Sometimes when soured the stuff is made up in 


74 


CEMENTS AND CONCRETES 


a large heap, and worked np again as required for 
use. This method makes a sound, reliable mortar. In 
some parts lime slaked as above is mixed with an equal 
part of run lime. This latter method makes the coarse 
stuff “fatter” and works freer. All slaked limes have 
a greater affinity for water than the mechanically 
ground limes. 

Grinding is another process for making mortar or 
“lime,” and if made with any kind of limestone is 
beneficial. It thoroughly mixes the material, increases 
the adhesion, adds to the density, and prevents blister¬ 
ing. When there is a mortar-mill, either ground or 
lump lime can be used, and the coarse stuff may be 
made in the proportion of 1 part lime and 3 parts 
sand. The lime should be left in the mill until thor¬ 
oughly reduced and incorporated, but excessive grind¬ 
ing is detrimental The process should not be con¬ 
tinued more than thirty minutes. Both material and 
strength is economized if lump lime is slaked before 
being put in the mill. 

When a mortar-mill is used for grinding the lime, 
the sand may. be partly or wholly dispensed with, and 
excellent results are obtained by using old broken bricks 
(clean and well burnt), stone chippings, furnace cin-‘ 
ders (free from coal), or slag. It is most essential in 
all cases that the materials used should be perfectly 
clean. It should be "Borne in mind that a complete in¬ 
corporation of the ingredients is essential in- the slak¬ 
ing and mixing for coarse stuff, whether done by hand 
or machine. The sand or other material used can be 
tested by washing a portion in a basin of clean water, 
then sifting through a fine sieve. If there is an undue 
residue of clay, fine dust or mud in the water or sieve, 
the whole of the aggregate should be washed or re- 


75 


PLASTER, LIME, ETC. 

jected. Lias lime should be mixed dry with sand and 
damped down for seven or ten days to ensure slaking. 
It should not be used fresh for floating or rendering. 
Pure or rich limes are not so well adapted for outside 
work, or places exposed to the action of damp, as hy¬ 
draulic limes. Mortar should be well tempered before 
using. Pliny states that it was an ancient practice to 
beat the mortar for a long time wdth a heavy pestle 
just before being used, the effect of which wmuld be 
not only more thoroughly to mix the materials, but to 
take from the outside of the sand the compound of 
lime and silica (if such had been formed during the 
period of seasoning) and by incorporating it with the 
mass, dispose it more rapidly to consolidate. Smeaton 
found that well-beaten mortar set sooner and became 
harder than mortar made in the usual way. Mortar 
made from hydraulic limes should be mixed as rapidly 
as is compatible with the thorough incorporation of the 
materials, and used as soon as practicable after mixing, 
because if put aside for any length of time its setting 
properties will deteriorate. 

Pure limes may be rendered hydraulic by mixing 
them with calcareous clays or shales, which have been 
so altered by the agency of heat that the silica they con¬ 
tain has to some extent assumed the nature of soluble 
silica. In good coarse stuff each granule of sand is 
coated over with the lime-paste so as to fill the inter¬ 
stices; the lime-paster is to hold the granular sub¬ 
stances in a concrete form. If too much lime-plaster 
is present, it is called “too fat”; if the lime-paster is 
deficient it is “too lean” or “poor.” This can be 
tested by taking up a portion on a trowel; the “fat” 
will cling to the trowel while the “lean” will run off 
like wet sand. The coarse stuff can be tested by mak- 


76 


CEMENTS AND CONCRETES 


ing briquettes and slowly drying; the good will stand 
a great pressure, whereas the bad will not-—in some 
cases falling to pieces. Some coarse stuff will appear 
“fat” on the trowel, but it may be the fatness of mud, 
not the fatness of lime, because sometimes sand is 
adulterated with fine-screened earth. When this stuff 
is made in the form of briquettes and dried, it will be 
extremely friable and easy to crush; or if put into 
water until soft, the earthy matter can be seen. Fine- 
screened earth, when dry and in bulk, does not seem 
an objectionable material; but in a wet state it is dirt 
or mud, and should at once be sent off to the works. 
All limes increase in strength by the addition of sand, 
being the reverse of Portland cement, which is weak¬ 
ened by this addition. Mr. Read made four samples 
of mortar with the proportions of ground lime and sand 
as follows: “Ground lime mixed with 4, 6, 8 and 10 
parts of clean washed sand to 1 part of ground lime 
respectively. All set and went hard. One of each 
was placed in water; that made with 4 parts of sand 
expanded and went to pieces; those with 6, 8 and 10 
parts of sand remained whole, and continued to get 
harder.” The addition of a small proportion of brick 
dust to mortar will harden and prevent the disinte¬ 
gration of mortar. The proportions are 1 part of brick 
dust, 2 parts of sand and 1 part of lime, mixed dry 
and tempered in the usual way. 

Adhesive Strength .—The adhesive strength of mortar 
varies according to the amount of sand used. The 
more sand used in the mortar, the less its adhesion. 
The following table shows the force required to tear 
apart bricks bedded in mortar made with the usual 
proportions of sand at the end of twenty-eight days: 


PLASTER, LIME, ETC. 77 


Adhesive Strengths of Limes and Cements. 


Fat lime and sand 

(1 to 3) 

4% lbs. per Sq. In. 

Common lias lime and sand 

«( 

g it it il ii 

<( n a a a 

(1 to 4) 

6% “ “ “ “ 

Portland cement “ “ 

(1 to 4) 

23 “ “ “ “ 

(< a a a 

(1 to 6) 

15% “ “ “ “ 


The old mortar which was held in such high esteem 
by the Romans is said to have consisted of lime mixed 
with pnzzolana or trass. Trass is a material similar 
in its nature to puzzolana, obtained from extinct vol¬ 
canoes in the valley of the Rhine, also in Holland, and 
is largely employed in engineering works. The name 
trass is derived from a Dutch word meaning a binding 
substance. Much has been written and said about the 
ancient and the old Roman mortars, but it may be 
safely said that, from the year one up to the present 
time, no cement or mortar has the strength, or could 
excel, or stand our variable climate as well as Portland 
cement. The primary cause of the premature deca> 
which takes place in stuccos and cements, when used 
externally as a coating to walls, is the presence of 
muddy earth and decayed animal and vegetable matter 
in the sand used in the lime and cement. To this may 
be added the frequent impurities in the limes and ce. 
ment themselves. The impurities in the sand may be 
eradicated by a thorough washing, and the lime should 
be carefully selected, prepared and manipulated. Hav¬ 
ing now briefly reviewed the principal parts and 
process of mortar, the practical conclusions to be 
drawn are, that the quality of the lime is of as great 
importance as the quantity, and thorough slaking is 
imperative; that the proportions of sand may vary con- 






78 


CEMENTS AND CONCRETES 


siderably, and that it should be coarse and irregular in 
size, and of a clean and hard nature. 

The Hardening of Mortar .—According to the results 
obtained from tests and experience, the hardening of 
mortar is due to several causes acting collectively. 
These causes appear to be absorption of carbonic acid 
from the atmosphere, and the combination of part of 
the water with the lime which act upon the sand, dis* 
solve and unite with some of the silica of the sand is 
composed, thus forming a calcium silicate (silicate of 
lime). Some authorities state that the silicate of lime 
is formed by the reaction of lime and silicate of mor¬ 
tar, and to this is due the hardness of old mortar. In 
mortar from the pure lime, the initial setting is due 
to the evaporation of water, and to the production of 
minute crystals of hydrate of lime, which slowly ab¬ 
sorbs carbonic gas from the air, the rapidity of this 
absorption necessarily decreasing in proportion to the 
difficulties presented to the free access of air. The 
setting and hardening of hydraulic limes are due mainly 
to crystallization brought by the action of water on 
the silicate of lime and not mere absorption of carbonic 
gas from the atmosphere, as is the case of fat limes. 

The Romans were convinced that it was owing to 
prolonged and thorough slaking that their works be¬ 
came so hard, and were not defaced by cracks. Al¬ 
berti mentions that he once discovered in an old trough 
some lime which had been left there five hundred 
years, as he was led to believe by many indications 
around it, and that the lime was as soft and as fit to 
be used as if it had been recently made. Common mor¬ 
tar made of rich lime hardens very slowly, and only 
by the evaporation of the water of the mixture, and by 
the absorption of carbonic acid from the atmosphere, 


PLASTER, LIME, ETC. 


79 


with which it forms a crystalline carbonate of lime. 
This process, however, is so slow, that it gave rise to 
the French proverb that “Lime at a hundred years old 
is still a baby”; and there is a similar proverb among 
Scotch masons, “When a hundred years are past and 
gane, then gnde mortar turns into stane.” Mortar 
from the interior of the pyramids, where it has been ex¬ 
posed to the action of the air, still contains free lime, 
although it is five thousand years old. It has been 
ascertained that in rich lime mortars the carbonic acid 
penetrates about one-tenth of an inch into the joint in 
the first year, forming a skin or film which opposes the 
further absorption of carbonic acid, except at a decreas¬ 
ing ratio, so that the lime remains soft for an indefi¬ 
nite period. In illustration of this several cases have 
been cited, amongst others one by General Treussart, 
who, in the year 1822, had occasion to remove one of 
the bastions erected by Vauban in 1666. After these 156 
years the lime in the interior was found to be quite 
soft. Dr. John, of Berlin, mentions that in removing 
a pillar of 9 ft. diameter in the Church of Saint Peter, 
Berlin, eighty years after erection, the mortar was found 
to be quite soft in the interior. 

General Pasley mentions several instances at Dover 
Harbor, and at Chatham dock yard, the latter in par¬ 
ticular, when part of the old wall was pulled down in 
the winter of 1834. The workmen were obliged to blast 
the brickwork fronting the river, which had been built 
with Roman cement, but the backing, done with common 
lime mortar, was in a state of pulp; the lime used had 
been prepared from pure limestone or chalk. But it 
is unnecessary to go back so far for knowledge of the 
absence of the setting quality in the rich limes, as 
there have been frequent experiences of it in the pres- 


80 


CEMENTS AND CONCRETES 


ent age. While these remarks are true of the richer 
limes, many of our limes are comparatively poor in 
carbonate, and associated with silica, alumina, mag¬ 
nesia and oxide of iron, which may either be partially 
combined in the natural state, or enter into combina¬ 
tion with the lime during the process of calcination, 
and these limes might be termed slightly hydraulic. 

M. Landrin, who submitted to the French Academy 
the results of some experiments on the hydraulicity and 
hardening of cements and lime, came to the conclusion 
that (1) silicates of lime raised to high temperature 
set with difficulty, and in any case do not harden in 
water; (2) for the recalcination of cements to exert 
a maximum influence on the setting, in connection with 
water of the compound obtained, the process must be 
carried sufficiently far for the limes to act on the silica 
so as to transform it into hydraulic, and not fused 
silica; and (3) carbonic acid is an indispensable factor 
in the setting of siliceous cements, in as much as it is 
this substance which ultimately brings about their hard¬ 
ening. The comparative strengths of various mortars 
are shown in the following table: 


Comparative Strength of Grey Lime and Portland Cement Mortar, also Portland Cement 

Mortar with the addition of Lime and Mortar.—R edgrave. 


PLASTER, LIME, ETC. 


81 


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82 


CEMENTS AND CONCRETES 


Magnesia in Mortars .—Magnesia plays an important 
part in the “setting” of hydraulic limes as well as in 
Portland cement. Vicat, after many experiments, was 
led to recommend magnesia as a suitable ingredient of 
mortars to be immersed in the sea, stating that if it 
could be obtained at a cost that would admit its appli¬ 
cation to such purposes, the problem of making con¬ 
crete unalterable by sea water would be solved. Gen¬ 
eral Gillmore, speaking of the American lime and ce¬ 
ment deposits, says: “Magnesia plays an important 
part in the ‘setting’ of mortars, derived from the ar- 
gillo-magnesian limestone such as those which furnish 
the Rosendale cements. The magnesia, like the lime, 
appears in the form of a carbonate. During calcination 
the carbonic acid is driven off, leaving protoxide of 
magnesia which comports itself like lime in the pres¬ 
ence of silica and alumina, by forming silicate of mag¬ 
nesia and aluminate of magnesia. These compounds 
become hydrated in the presence of water, and are 
pronounced by Vicat and Chatoney to furnish gangues, 
which resist the dissolving action of sea water better 
than the silicate and aluminate of lime. This statement 
is doubtless correct, for we know that all of these com¬ 
pounds, whether in air or water, absorb carbonic acid, 
and pass to the condition of subcarbonates, and that 
the carbonate of lime is more soluble in water holding 
carbonic acid and certain organic acids of the soil in 
solution than the carbonate of magnesia. At all exeats, 
whatever may be the cause of the superiority, it is 
pretty well established by experience that the cements 
derived from argillo-magnesian limestones furnish a 
durable cement for construction in the sea.” 

In Marshal Vaillant’s report to the French Academy 
of Sciences, from the Commission to which Chatoney 


PLASTER, LIME, ETC. 


83 


and Rivot’s paper was referred in 1856, this superiority 
of the magnesian hydrates is distinctly asserted. A few 
years ago the French Government Office of Civil En¬ 
gineers made a series of comparative tests on three sam¬ 
ples each of French, English and German cement, in 
which the results are given in favor of the German 
cement, which contains magnesia to the extent of 2.4 
per cent, against 0.26 in the English and 0.32 in the 
French, and summed up thus: “A great value partly 
due to the higher percentage of magnesia contained in 
it.” Gillmore further says that magnesian limestone 
furnishes nearly all the hydraulic cement manufactured 
in the western part of the State of New York. At 
East Vienna it has been used for cement, and at Akron, 
Erie County, N. Y., a manufactory of some extent is in 
operation. Vicat says: “Having analyzed several old 
mortars, with the view of discovering, if possible, to 
what their superior durability might be attributed, I 
found, in some excellent specimens of very old mortar, 
magnesia to exist in considerable proportions.” The 
limestones, therefore, from which these mortars were 
prepared must have contained the silica and magnesia 
as constituent ingredients; and it is to be remembered 
that it is the presence of these substances which com¬ 
municates the property of hardening under water. Pro¬ 
fessor Scorgie says of carbonate of magnesia: “Mag¬ 
nesium carbonate is a substance very similar to carbon¬ 
ate of lime; it loses its carbonic acid in burning, com¬ 
bines with silica, etc., and behaves generally in the 
same way; it does not slake, however, on being wetted, 
but combines with the water gradually and quietly sets 
to some extent in doing so. Magnesium carbonate com¬ 
bined with lime, reduces the energy of slaking, and in¬ 
creases that of the ‘setting’ process; when other sub- 


84 


CEMENTS AND CONCRETES 


stances are present, its behavior and combination with 
them are similar to those of lime. When carbonate of 
magnesia is present in sufficient quantity, say about 30 
per cent., it renders lime hydraulic independently of 
and in the absence of clay.” Colonel Pasley also, by 
experiments, demonstrated that magnesium limestones 
are suitable for hydraulic mortars. 

The foregoing assertions that magnesium carbonate, 
combined with lime, reduces the energy of slaking and 
increases that of the “setting” processes are satisfac¬ 
tory and conclusive. Many such evidences showing the 
value of magnesia in hydraulic mortars might be quoted, 
but perhaps these are sufficient. 

Effects of Salt and Frost in Mortar .—Few experi¬ 
ments have as yet been made to test the general effects 
of salt in mortars, though as a preventive of the effects 
of frost it has been tried with varying results. 

In some experiments, designed to ascertain the effect 
of frost upon hydraulic limes and cement gauged with 
and without addition of salt to the water, cubes of stone 
were joined together with cement mixed with water 
ranging from pure rainwater to water containing from 
2 to 8 per cent, of salt. Before the cement was set the 
blocks were exposed in air at a temperature varying 
from 20 to 32 degrees Fahr., after which they were 
kept for seven days in a warm room. At the end of 
this time the samples were examined. The cement 
made with water was quite crumbled, and had lost all its 
tenacity. The cement made with water containing 2 per 
cent, was in better condition, but could not be described 
as good; while that containing 8 per cent, of salt had not 
suffered from its exposure to the lowest temperature 
available for the purpose of experiment. It is suggested 
as possible that the effect of the salt was merely to pre- 


PLASTER, LIME, ETC. 


85 


vent the water in which it was dissolved from freezing at 
the temperature named, and so permitted the cement 
to set in the ordinary way. But it must he allowed 
that in practice, salt dissolved in the water for mixing 
mortar has been successfully used to resist the effect 
of frost. A solution of salt applied to new plastered 
walls in the event of a sudden frost will protect the 
work from injury. The addition of a small portion 
of sugar will improve its adhesion, and increase the 
frost-resisting powers. 

Salt takes up the vapors from the atmosphere, caus¬ 
ing the work to show efflorescence, and in some instances 
to flake, especially in external work. That some en¬ 
gineers believe there is virtue in salt water is beyond 
doubt, because salt water has been named in their speci¬ 
fications for the gauging of concrete. Salt in Portland 
cement seems to act somewhat differently; as regards 
efflorescence it shows more in this material than in lime 
mortar. Salt should not be used in Portland cement 
work that has to be subsequently painted. According to 
the results of tests of mortar used for the exterior 
brick facing of the Forth Bridge piers below water they 
show a good average tensile strength. One part of 
Portland cement and one part of sand were slightly 
ground together in a mill with salt water, and briquettes 
made from this gauge gave an average of 365 lbs. per 
square inch at one week, and 510 lbs. at five weeks after 
gauging. It would be interesting to note the condition 
of this mortar a century hence, time being the trying 
test for all mortars. 

A solution of commercial glycerine mixed with the 
setting stuff, or used as a wash on newly finished lime 
plaster work, is a good preventive of the evil effects of 
frost. Glycerine solution may also be used for the same 


86 


CEMENTS AND CONCRETES 


purpose on new concrete paving. Strong sugar water 
mixed with coarse stuff has some power in resisting 
frost. The quantity depends upon the class of lime, 
but the average is about 8 lbs. of sugar to 1 cubic yard 
of coarse stuff or setting stuff. The sugar must be dis¬ 
solved in hot water and the stuff used as stiff as pos¬ 
sible. 

Sugar With Cement .—Sugar or other saccharine mat¬ 
ter mixed with cement has been tried with varying 
success. It is well known that saccharine is used with 
mortars in India. According to some experiments made 
in this country, the results obtained were that the addi¬ 
tion of sugar or molasses delayed the setting of the 
mortar, the retardation being greater when molasses was 
used. When certain proportions were not exceeded, the 
strength of the mixture was that of the pure cement. 
Less than 2 per cent, of sugar must be added to Port¬ 
land cement, and less than 1 per cent, to Roman, other¬ 
wise the mortar will not hold together. The sugar ap¬ 
pears to have no chemical action on the other materials, 
crystals of it being easily detected on the broken sur¬ 
faces, the increased binding power of the cement 
brought about by the addition of sugar being due more 
to mechanical than chemical causes. In my own experi¬ 
ments with sugar added to Portland cement for cast¬ 
ing deep undercut ornament figures and animals out 
of gelatine moulds, the results at first were very irregu¬ 
lar, some casts attaining great hardness, while others 
crumbled to pieces. The time of setting also varied 
considerably. Three different brands of cement were 
used, and it was found that the cement containing the 
most lime required more sugar than the lowest limed 
cement, but the average is about 1% per cent, of added 
sugar. The sugar must be dissolved in the water used 


PLASTER, LIME, ETC. 


87 


for gauging. The setting and ultimate hardness is also 
influenced by the atmosphere. The casts should be kept 
in a dry place until set and dry, before exposing them 
to damp or wet. Portland cement has a tendency (es¬ 
pecially if over limed) to “fur” gelatine moulds, but 
the sugared cement leaves the moulds quite clean. 

In experiments by Austrian plasterers, mixtures of 
1 part of cement and 3 parts sand, and 10 per cent, of 
water, and of pure cement with as much water as was 
necessary to give the mass plasticity, were prepared. 
From 1 to 5 per cent, of powdered sugar was well mixed 
with the dry cement. The cement used was of inferior 
quality, the sand being ordinary building sand, and 
not the so-called “normal” sand, which is of a superior 
quality. They were left to harden in a dry place, and 
not under water. For each series of samples made with 
sugar a comparative series without sugar was prepared, 
all the samples being made by the same man, under the 
same conditions and with the same care. The tenacity 
was ascertained by Kraft’s cement-testing machine. The 
strength was far below that prescribed and generally 
obtained. It should be mentioned that the samples with 
sugar (especially those of pure cement) showed a strong 
tendency during the first twenty-four hours to combine 
intimately with the smooth china plate on which they 
were placed to swell, and the results of the trial showed 
that with mixtures of cement and sand, and by harden¬ 
ing in a dry place, the binding effect may be increased 
by the addition of sugar, which reached its maximum 
with from 3 to 4 per cent, of sugar added. With pure 
cement the binding effect was not much increased. If 
the sugar used for gauging had been dissolved, and not 
mixed dry, the results would have proved better. 


88 


CEMENTS AND CONCRETES 


Sugar in Mortar .—Most writers have supposed that 
the “Old Roman Mortars” contained strong ale, wort, 
or other saccharine matter, and it is probable that the 
use of sugar with lime passed from India to Egypt and 
Rome, and that malt or other saccharine matter was 
used in their mortars. The addition of sugar to water 
enables it to take up about 14 times more lime than water 
by itself. The following is an extract from the Roorkee: 
“It is common in this country to mix a small quantity of 
the coarsest sugar, ‘goor,’ or ‘Jaghery,’ as it is termed 
in India, with the water used for mixing up mortar. 
Where fat limes alone can be produced their bad quali¬ 
ties may in some degree be corrected by it, as its influence 
is very great in the first solidification of mortar. This is 
attributed to the fact that mortars made of shell lime 
have stood the action of the weather for centuries owing 
to this mixture of Jaghery in their composition. Experi¬ 
ments were made on bricks joined together by mortar 
consisting of 1 part of common shell lime to iy 2 of sand, 
1 lb. of Jaghery being mixed with each gallon of water. 
The bricks were left for 13 hours, and after that time 
the average breaking weight of the joints in 20 trails 
was 6y 2 lbs. per square inch. In twenty-one specimens 
joined with the same mortar, but without the Jaghery, 
the breaking weight was 4 y 2 lbs. per square inch.” 

The Madras plasterers make most beautiful plaster 
work, almost like enamelled tiles, the shell lime being 
mixed with Jaghery. The surface takes a fine polish 
and is as hard as marble, but it requires a good deal of 
patient manipulation. Dr. Compton has made some ex¬ 
periments with sugar gauged with cements and mortars, 
and says, “That in medicine there are two kinds of lime- 
water, one the common lime-water, that can be got by 
mixing lime and water, and it is particularly noted 


PLASTER, LIME, ETC. 


89 


that, add as much lime as you like, it is impossible to get 
water to dissolve more than half a grain of lime in one 
ounce, or about two teaspoonfuls of water. But by add¬ 
ing 2 parts of white sugar to 1 part of lime, there is a 
solution obtained which contains about 14^ times more 
lime in the same quantity of water. Here it is to be ob¬ 
served—and it is a most important point—that there are 
hot limes, such as Buxton, which if they be incautiously 
mixed with them, will burn the sugar, make it a deep 
brown color, and convert it into other chemical forms, 
and possibly destroy its value in mortar.” 

The Jaghery sugar used in India is sold in the London 
market at about a penny a pound. Treacle seems to be 
the most promising form of saccharine matter; beetroot 
sugar is not good for limes or cements. There is a rough 
unrefined treacle which is very cheap, and it is supposed 
would have an excellent effect. 

Herzfeld states that he used coarse stuff, consisting of 
1 part of lime to 3 of sand, to which about 2 per cent, 
of sugar had been added, to plaster some walls in the 
new building of the Berlin Natural History Museum, 
and on the day following he found the lime plaster had 
hardened as if gauged with plaster. He also found it 
useful in joining bricks, and recommends the coarse stuff 
to be fresh made, and not with a great proportion of 
water; and states that good molasses will yield as good 
results as sugar. 

Lime Putty .—This material is prepared in a similar 
way to run lime intended for coarse stuff. It is run 
through a finer sieve into a box or pit. If the latter is 
used the interior should be plastered with coarse stuff to 
prevent leakage and keep the putty clean. For good 
work the best class of lump lime should be used. The 
putty should be allowed to stand for at least three 


90 


CEMENTS AND CONCRETES 


months before it is used. For common work the lump 
lime for making coarse stuff, putty and setting stuff is 
often run into one pit. The putty at the end farthest 
from the sieve, being the finest, is retained for putty and 
for making setting stuff, and the remainder, or coarser 
portion, being used for coarse stuff. In many instances 
the putty is left for months in an unprotected state dur¬ 
ing the progress of the building, which is wrong. It may 
be kept for an indefinite time without injury if protected 
from the atmosphere, and therefore it should be covered 
up to resist the action of the air, as it absorbs the car¬ 
bonic acid gas and thus becomes slightly carbonated and 
loses to a certain extent its causticity, and consequently 
its binding and hardening properties. 

Pliny states that the old Roman limes were kept in cov¬ 
ered pits. If a small portion is taken off the top of the 
putty it will be found not only dry, but scaly, short and 
inert ; whereas a portion taken from the. middle, or up to 
the part carbonated, will be found to be of an cily and 
tenacious nature. A cute plasterer always selects the 
putty furthest from the sieve for mitring purposes, as it 
is the finest. 

Setting Stuff .—This material is composed of lime 
putty and washed fine sharp sand. The proportion of 
sand varies according to the class of lime and kind of 
work, but the average is 3 parts cf sand to 1 of putty. 
The various proportions are given where required for the 
different works. Setting stuff is used for finishing coat 
of lime plastering. It is generally made on a platform 
of scaffold boards, and sometimes in a bin. The putty 
and sand are thoroughly mixed together by aid of a 
larry. The sand should be sized by washing it through a 
sieve having a mesh of the desired size. In some districts 
it is made by pressing or beating the putty and sand 


PLASTER, LIME, ETC. 


91 


through a “punching sieve” into a tub. Setting stuff is 
less liable to shrink and crack, and is improved generally 
if it is allowed to stand after being made until nearly 
hard, but not dry, and then “knocked up” to the re¬ 
quired consistency with water (preferably lime-water) 
and the aid of a shovel and larry. While the stuff is 
firming by evaporation it should be covered up to protect 
it from dust and atmospheric influences. It should be 
used as soon as “knocked up.” Setting stuff may be 
colored to any desired tint, and also mixed with various 
ingredients to obtain a brilliant and marble-like surface. 

Haired Putty Setting .—Haired putty was formerly 
used to a very considerable extent as a setting coat in 
districts where the local lime was of a strong or hydraulic 
nature, not very readily manipulated when mixed with 
sand, as used for setting stuff. This material is com¬ 
posed of fine lime putty and well-beaten white hair. The 
hair was thoroughly mixed with the putty to toughen 
and prevent it from cracking. To such an extent was hair 
added that in some instances the setting coat when 
broken had the appearance of white felt. This class of 
setting stuff is now seldom used. 

Lime Water .—This water has many medicinal virtues, 
and is a simple and inexpensive remedy for cuts and 
bruises. Plasterers are generally healthy and free from 
any infectious diseases. This may be partly owing to 
their almost constant contact with lime. Lime water, 
used as a wash, will harden plaster casts. It is also used 
when scouring and trowelling setting stuff to harden the 
surface. 

Hair .—Hair is used in coarse stuff as a binding me¬ 
dium, and gives more cohesion and tenacity. It is usu¬ 
ally ox-hair (sometimes adulterated with the short hair 
of horses). Good hair should be long, strong and free 


CEMENTS AND CONCRETES 


92 

from grease or other impurities. It is generally obtained 
in a dry state in bags or bundles. This dry hair should 
be well beaten with two laths to break up the lumps, as, 
unless the lumps are thoroughly broken so as to sepa¬ 
rate the hair they are only a waste, and worse than no 
hair at all, since the lumps have no binding power and 
will cause a soft weak spot in the plaster when laid. 
Many failures of ceilings have been caused by the hair 
not being properly beaten and mixed. Human hair is 
sometimes used for jerry work. Goats’ hair is often used 
here. Hair is usually obtained direct from the tanners’ 
yard, fresh and in a wet state. This makes the best 
work, as it is much stronger and mixes freely. Hair 
should never be mixed with hot lime, and with no mor¬ 
tars until nearly ready for using, because wet or hot 
lime weakens the hair, more especially if dry. Coarse 
stuff for first coating on lath work requires more hair 
than for brick or stone work. When coarse stuff is made 
in a mill the hair should not be added until the stuff is 
ground, as excessive grinding injures it. 

Fibrous Substitutes for Hair .—Manila fiber as a sub¬ 
stitute for hair in plaster work has been the subject of 
experiments in this country. One of the most conclu¬ 
sive of these tests was made by four briquettes or plates 
of equal size, one containing manila hemp, a second sisal 
hemp, a third jute and a fourth goats’ hair of the best 
quality. The ends of the plates were supported and 
weights suspended from the middle. The result showed 
that plaster mixed with goats’ hair broke at 1 44y 2 
lbs. weight, the jute at 145 lbs., the sisal at 150, and the 
manila at 195, in the latter case the hemp not breaking, 
but cracking, and though cracked in the center, the lower 
half of this plate, when it was suspended, held onto the 
upper half, the manila securing it fast. The three other 


PLASTER, LIME, ETC. 


93 


plates were broken—that is, the two parts of each plate 
had severed entirely. Another experiment consisted in 
mixing two barrelfuls of mortar, each containing equal 
portions by measure of sharp sand and lime, one of the 
barrels, however, being mixed with a proper quantity by 
measure of manila hemp, cut in lengths of 1% to 2 
inches, and the other of best goats ’ hair. On being thor¬ 
oughly mixed with the usual quantity of water, the re¬ 
spective compounds were put in the barrels and stored 
away in a dry cellar, remaining unopened for nine 
months. On examination the hair mortar crumbled.and 
broke apart, very little of the hair being visible, showing 
that the hair had been consumed by the action of the 
lime; but the other, containing the hemp, showed great 
cohesion. It required quite an effort to pull it apart, 
the hemp fiber permeating the mass and showing little 
or no evidence of any injury done to it by the lime. 

Sawdust as a Substitute for Hair .—Sawdust has been 
used as a substitute for hair, also for sand in mortar for 
wall plastering. It makes a cheap additional ^aggregate 
for coarse stuff. Sawdust mortar stands the effects of 
rough weather and frost when used for external plaster¬ 
ing. The sawdust should be used dry and put through a 
coarse sieve to exclude large particles. I have used it 
with plaster for both run and cast work. It proved use¬ 
ful for breaks of heavy cornices by rendering the work 
strong and light for handling. Some kinds require soak¬ 
ing or washing, otherwise they are liable to stain the 
plaster. Several patents have been issued in America for 
the use of sawdust in place of hair and of sand. One of 
these is for the use of equal parts of plaster, or lime and 
sawdust; another is for the use of 4% parts each slaked 
lime and sawdust to 1 part of plaster, % part °f glue 
and 1-16 part of glycerine, with a small part of hair. 


94 


CEMENTS AND CONCRETES 


Kahl’s patent plaster consists of 35 per cent, of saw¬ 
dust, 35 per cent, of sand, 10 per cent, of plaster, 10 per 
cent, of glue, and 10 per cent, of whiting. 

Sand .—Sand is the most widely distributed substance 
in nature, not only in the mineral but also in the animal 
and vegetable kingdoms. Clay contains no silica (the 
chemical name for sand). Sand is the siliceous particles 
of rocks containing quartz, production by the action of 
rain, wind, wave and frost. Some kinds of sand are also 
found inland; the deposits mark the sites of ancient 
beaches or river beds. Sand is classed under various 
heads, viz., calcareous, argillaceous and metallic. Sand 
varies in color according to the metallic oxides contained 
in them. Pew substances are of more importance than 
sand for plastic purposes. Its quality is of primary im¬ 
portance for the production of good coarse stuff, set¬ 
ting stuff, and for gauging with Portland or other 
cements used for plaster work. Its function is to induce 
the mortar or cement to shrink uniformly during the 
process of setting, hardening or drying, irregular shrink¬ 
age being the general cause of cracking. Sand is also a 
factor in solidity and hardness; while being of itself 
cheaper and used in a larger proportion than lime or 
cement, it decreases the general cost of materials. There 
are three kinds—pit, river and sea sands. They gen¬ 
erally contain more or less impurities, such as loam, 
clay, earth and salts, necessitating their being well 
washed in water, more especially for the finishing coats 
of plaster or cement work. Pit sand is sometimes found 
quite clean; it is generally sharp and angular. River 
sand is fine grained, not so sharp as pit sand, but makes 
good setting stuff. Sea sand varies in sharpness and 
size, and for plastering it should be washed to free it 
from saline particles which cause efflorescence. 


PLASTER, LIME, ETC. 


95 


Regarding the use of sand in mortars, it may almost 
be spoken of as a necessary evil. Sand is necessary to 
give body and hardness to an otherwise too soft and 
plastic material, and the coarser and cleaner the better, 
as the coarse particles allow the carbonic acid to pene¬ 
trate further into the body of the mortar, and assist in 
the hardening process for this reason. In the case of 
cements of all kinds sand is only good for lessening the 
cost of the aggregate, and in the case of the majority of 
sands in daily use in most places the strength is reduced 
out of all proportion to the saving effected. Brunei, in 
the Thames Tunnel, was so convinced of this that he used 
pure Portland cement in the arches; and General Pas- 
ley, treating of this, recommends that only pure cement 
should be used on all arduous works. 

As to the quality of sands, they are of very wide 
variety—so much so, that 1 part of an inferior or soft 
clayey sand will reduce the strength of mortar as much 
as 3 or 4 parts of clean sharp granitic sand. This is well 
exemplified in the sand test, which is made with what is 
called standard sand, being a pure si-lecious sand sifted 
through a sieve of 400 holes to the square inch and re¬ 
tained on one of 900. 

Good sand for lime plaster should be hard, sharp, 
gritty and free from all organic matter. For coarse stuff 
and cement for floating coats it should not be too fine. 
Good sand for plaster work may be rubbed between the 
hands without soiling them. The presence of salt in sand 
and water is found not to impair the ultimate strength of 
most mortars; nevertheless it causes an efflorescence of 
white frothy blotches on plaster surfaces. It also ren¬ 
ders the mortar liable to retain moisture. 

Fine-grained sand is best for hydraulic lime; the 
coarse-grained is best for fat limes, and coarse stuffs and 


96 


CEMENTS AND CONCRETES 


Portland cements for floating. Sand should not be uni¬ 
form in size, but, like the aggregate for concrete, should 
vary in size and form. A composition of fine and coarse 
sand for coarse stuff, unless the sand is naturally so 
mixed, gives the best results, for as the lime will receive 
more sand in that way without losing its plasticity it will 
make a harder and stronger material, whether coarse 
stuff, setting stuff or for Portland cement work. If there 
is plenty of fine sand and a scarcity of coarse sand, they 
should be mixed in the proportion of 2 of coarse to 1 of 
fine. If on the other hand, there is plenty of coarse 
sand and a scarcity of fine, they should be mixed in the 
proportions of 2 of fine to 1 of coarse. The proportion of 
sand varies according to the different kinds and qualities 
of limes and cements, also purposes. Baryte is some¬ 
times used as a substitute for sand. Silver sand is used 
for Portland cement work when a light color and a fine 
texture is required. 

Mastic .—Mastic was formerly extensively used foi 
various purposes in which now Portland cement is chiefly 
employed. It is still used sometimes for pointing the 
joint between the wood frames of windows and the stone 
work. Mastic is waterproof, heat-resisting and adheres 
to stone, brick, metal and glass with great tenacity. Mas- 
tic is made in various ways. Some plasterers make their 
own. 

Scotch Mastic is composed of 14 parts of white or 
yellow sandstone, 3 parts of whiting and 1 part of lith¬ 
arge. These are mixed on a hot plate to expel any mois¬ 
ture and then sifted to exclude any coarse particles. It 
is then gauged with raw and boiled linseed oil in the 
proportion of 2 of raw to 1 of boiled oil. The sandstone 
is pounded or ground to a fine powdered state before 


PLASTER, LIME, ETC. 


97 


being: mixed. The surface to be covered is first brushed 
with linseed oil. 

Common Mastic is prepared as follows: 100 parts of 
ground stone, 50 parts silver sand or of fine river sand, 
and 15 parts of litharge. These are all dried and mixed 
and passed through a fine sieve; it then resembles fine 
sand. This mastic may be kept for any length of time in 
a dry place. When required for use it is gauged with 
raw and boiled linseed oil (in equal proportions) until 
of the consistency of fine stuff. It requires long and fre¬ 
quent beating and kneading—in fact, the more it is 
knocked up the better it works. Its fitness for use can 
be ascertained by smoothing a portion of the gauge*with 
a trowel. If there are any separate pa,rts of the differ¬ 
ent materials or bright spots seen the knocking-up must 
be renewed until it is of even texture. The addition of 15 
parts of red lead is sometimes used to increase the tenac¬ 
ity of the mastic. 

Mastic Manipulation .—The walls are prepared for 
mastic by raking out the joints and sweeping with a 
coarse broom, and the brick work well saturated with lin¬ 
seed oil. Narrow screeds about 1 inch wide are formed in 
plaster to act as guides for floating the work plumb and 
level. When laying the mastic it must be firmly pressed 
on and the floating rule carefully passed over the sur¬ 
face until it is straight and flush. The screeds are next 
cut out and the spaces filled in with extra stiff mastic. 
The whole surface is then finished with a beech or syca¬ 
more hand float, leaving a close and uniform texture. 
Mastic moldings are first roughed out with Medina or 
other quick-setting cement. The running mold is muffled 
so as to allow % inch for the mastic coat. 

Hamelein y s Mastic .—This mastic consists of sand and 
pulverized stone, china, pottery, shard, to which are 


98 


CEMENTS AND CONCRETES 


added different oxides of lead, as litharge, gray oxide 
and minium, all reduced to powder, to which again is 
added pulverized glass or flint stone, the whole being 
intimately incorporated with linseed oil. The propor¬ 
tions of the ingredients are as follows: To any given 
weight of sand or pulverized pottery ware add two-thirds 
of the weight of pulverized Portland, Bath or any other 
stone of the same nature. Then to every 550 lbs. of this 
mixture add 40 lbs. of litharge, 2 lbs. of pulverized glass 
or flint stones, 1 lb. of minium and 2 lbs. of gray oxide 
of lead. The whole must be thoroughly mixed together 
and sifted through a sieve, the fineness of which will de¬ 
pend on the different purposes for which the mastic is 
intended. The method of using is as follows: To every 
30 lbs. of the mastic add 1 quart of linseed oil and well 
mix together either by treading or with a trowel. As it 
soon begins to set, no more should be mixed at a time 
than is requisite for present use. Walls or other sur¬ 
faces to be plastered with this material must first be 
brushed with linseed oil. 

Mastic Cement .—Mix 60 parts of slaked lime, 35 parts 
of fine sand and 3 parts of litharge, and knead them to 
a stiff mass with 7 to 10 parts of old linseed oil. The 
whole mass must be well beaten and incorporated until 
thoroughly plastic. This mastic cement assumes a fine 
smooth surface by troweling. It is impervious to damp 
and is not affected by atmospheric changes. 


TERMS AND PROCESSES. 


The following descriptions are suited to most locali¬ 
ties, though there are districts in the East and South 
that vary somewhat from the processes as described; 
the difference, however, is so trifling that the regular 
plasterer will have no trouble in reconciling such differ¬ 
ences. 

Three-Coat Work. t—Three-coat work is usually speci¬ 
fied by architects for all good buildings, but sometimes 
two-coat work is specified for inferior rooms, closets, at¬ 
tics or cellars in the same building. Three-coat work 
makes a straight, smooth, strong and sanitary surface for 
walls and ceilings when properly executed. The follow¬ 
ing is the process for three-coat work ? which consists of 
first-coating, floating and setting. 

First-Coating. —“First-coating ’ 9 is termed in the 
United States “ scratch-coating. ’ ’ It is executed by lay¬ 
ing and spreading a single coat of coarse stuff upon the 
walls and ceilings to form a foundation for the subse¬ 
quent floating and setting coats. Coarse stuff for first- 
coating should be uniformly mixed or “knocked up,” as 
commonly called. It should contain more hair than that 
used for floating, so as to obtain a strong 'binding key on 
the lath-work and form a firm foundation for the float¬ 
ing coat. Coarse stuff may be tested by lifting some 
from the heap on the point of a trowel. If it is suffi¬ 
ciently haired and properly mixed the stuff should cling 
to the trowel when held up and the hairs should not be 
more than 1-16 inch apart. It should be stiff enough to 
cling and hold up when laid, yet sufficiently soft and 

99 


100 


CEMENTS AND CONCRETES 


plastic to go through the interstices between the laths. 
Unless the stuff is made to the proper consistency it will 
“drop”—that is, small patches where the excess water 
accumulates or at weak or too wide spaced laths will fall 
soon after being laid. 

When first-coating ceilings, the coarse stuff should be 
laid diagonally across the laths, a trowelful partly over¬ 
lapping the previous one, the one binding the other. By 
laying the stuff diagonally the laths yield less, present a 
firmer surface and are not so springy as when laid across 
or at right angles to them. Laying the stuff diagonally 
and overlapping each trowelful helps to retain the stuff 
in its place, which otherwise is apt to “ drop. ’ ’ The stuff 
should be laid on with a full-sized laying trowel, using 
sufficient pressure to force it between the laths and to 
go sufficiently through to form a rivet and lap or clinch 
on the upper sides of the lathing. The stuff should be 
laid fair and as uniform in thickness as possible. The 
thickness should not exceed % inch or be less than % 
inch. If too thick it tends to weigh down the lath work 
and is apt to crack; if too thin the subsequent scratching 
is liable to cut the coat down or nearly to the laths, thus 
leaving a series of small detached pats which are un¬ 
stable and form a weak foundation for the floating coat 
and are a source of cracks and often the cause of the 
work falling when subjected to vibration. A thickness 
of y 2 inch gives the best results. 

Scratching .—Scratching is sometimes termed “scor¬ 
ing,” also “keying.” It is done with a wooden or iron 
scratch, which may have from one to five points. 
Scratching is scoring the surface of the first coat to 
obtain a key for the following coat. The first-coating 
should be allowed to stand for an hour or two to allow 
the stuff to get firm before proceeding with the scratch- 


TERMS AND PROCESSES 


101 


ing. If scratched while the stuff is soft it is apt to drop, 
and unless a man is careful and light in his working the 
scratch will go too deep and weaken the body and the 
rivets of first-coating. A wide scratch should be slightly 
angular at the points; if square, it should he drawn 
across the work in a slanting position so as to give an 
undercut key. The whole of the surface should be uni¬ 
formly scratched with a moderately sharp pointed 
scratch. The surface should he cross-scratched diag¬ 
onally. Square scratching cuts and weakens the rivets, 
especially when the scratch is drawn in the same line as 
the laths. Good work is generally scratched with a sin¬ 
gle lath. This, like other scratches, should he drawn in 
a slanting position, so as to give an undercut score. Sin¬ 
gle scratches is the best way for circular surfaces. First 
score it diagonally across the laths and then crossways 
diagonally, keeping the scoring rather square than loz¬ 
enge-shaped. When too pointed the acute angles are 
liable to be broken when laying the floating coat. The 
scores should not be more than l 1 /^ inch from center to 
center, or less than one inch from center to center. Close 
scoring weakens the body of the first-coating, while wide 
scoring affords insufficient key. Scratching with a single 
lath requires thrice or even more time than if done with 
a four or five pointed scratch, but the work is stronger, 
as the body and the rivets of the first coating are not 
cut too deep or otherwise weakened. In some instances— 
such as a thin body of first-coating already mentioned— 
the scoring is so deep that the body of the work is cut 
into a series of detached parts. By using a single lath 
or point the scoring is also more uniform and better un¬ 
dercut, thus obtaining a stronger surface and a better 
key for the floating coat. The additional time required 
for “single scratching” should be taken into considera- 


102 


CEMENTS AND CONCRETES 


tion, and annotated and allowed for when making speci¬ 
fications and estimating. . All scratching should be done 
uniformly, taking care not to miss any parts, especially 
round door and window frames, wood grounds or where 
there may be jarring or vibration. On the regular and 
proper scratching depends the key and stability of the 
succeeding coats. Scratching with the point of a trowel 
should not be permitted. The use of a trowel as a 
scratch is detrimental to the strength of the stuff and the 
key. The sharp edge of the trowel cuts the hair and 
thus weakens the stuff. The smooth and thin plate of the 
trowel leave's a smooth and narrow key; the smooth side 
of the key presents no attachment for the second coat, 
while the deep part of the key is too narrow to receive 
its due portion of stuff to fill it up, thus leaving a space 
for contained air and a more or less hollow and unsound 
body. 

Rendering .—The first coat on brick, stone or concrete 
walls is called rendering. Before laying the coarse stuff 
the superfluous mortar in the joints of brick or stone 
walls should be cleared off, as the mortar used by brick¬ 
layers and stonebuilders often contains live or imper¬ 
fectly slaked lime, which in many instances is the cause 
of the plaster work blowing or scaling off. The walls, 
whether of brick, stone or concrete, should be well swept 
with a hard coarse broom and thoroughly wetted to cor¬ 
rect the suction, which otherwise would absorb the requi¬ 
site moisture from the coarse stuff, causing it to become 
inert and dry, consequently weak and non-adhesive. In 
some cases the joints of brick-work should be raked out 
and the face of stone walls roughened by picking. The 
coarse stuff for rendering walls does not require so much 
hair or to be used so stiff as for coating lathwork. First- 
coating cr rendering is generally looked upon as a simple 


TERMS AND PROCESSES 


103 


process, but it should be carefully laid and scratched, as 
it is the foundation for the other work. 

Floating .—Floating or second-coating, termed ‘ 4 brown- 
mg,” is the laying of the second coat of coarse stuff on 
the first coat when dry to form a straight surface for the 
finishing coat. If the first coat has been standing for 
some time it should be well swept to clear off any dust 
that may have accumulated during the interval between 
the application of the coats. Where the coarse stuff is of 
a porous nature a damp brush should be passed lightly 
over the first coat as the work proceeds to prevent the 
moisture being sucked out of the second layer, which, if 
too dry, would tend to crack and fall away. The coarse 
stuff for floating should be used in a softer state than 
for first-coating, because when too stiff the extra press¬ 
ure required for laying is apt to crack the first coat on 
lath work. It also goes more freely and firmly into the 
recesses of the scratching. (It may be here mentioned 
that a mortar called “dogga” is extensively used in 
South Africa for plaster and building work. Dogga is 
the ground dug up and tempered with sand, about 2 to 
1 for rendering and floating. Heavy ground requires 
more sand. Lime is very expensive in that country and 
is only used for the best class of work.) Floating for 
lime plastering consists of four parts: (1) Plumbing 
and levelling “screeds” to act as bearing for the floating 
rule and running mold; (2) flanking or filling in the 
spaces between the screeds; (3) scouring; (4) keying the 
surface. These parts are performed as follows: 

Screeds .t—In good work the wall screeds are plumbed 
and the ceiling screeds levelled. Wall screeds are 
plumbed by forming “dots” at the top and bottom of 
the internal and external wall angles. If there are wood 
grounds to receive wood skirtings they are used instead 


104 


CEMENTS AND CONCRETES 




of bottom dots. The dots are made by 
driving two nails through the first coat 
into the studs or joints of the wall, 
allowing them to project about % inch 
beyond the face of the first coat. The 
position of the top nail should be imme¬ 
diately beneath the cornice bracket. If 
there is no bracket the depth of the 
cornice should be allowed for. The 
bottom nail is placed in a liue with the 
upper member of the skirting molding. 
The nails should be placed perpendicu¬ 
lar with each other, otherwise the 
plumb-bobline will not work in unison 
with the gauges. The dots are plumbed 
by means of a plumb-rule. If the walls 
are too high for an ordinary sized 
plumb-rule to be used a chalkline, with 
a plumb-bob attached, and two wooden 
gauges will be required. Illustration 
No. 3 shows the nails, gauges and 
plumb-bobline in position. BB are the 
nails in the wall, one just below the 
cornice bracket and the other a little 
above the floor line; AA are the gauges 
with the line hanging fair with their 
shoulders, being the correct position 
when the nails are plumb. The gauges 
are generally cut out of a strong lath. 
They must be made exactly to the same 
length. The plasterer at the top holds 
the end of one gauge on the top nail, 
with the chalk-line resting on the shoul¬ 
der of the gauge, while the plasterer 


NO. 3. 












TERMS AND PROCESSES 


105 


at the bottom holds the other gauge on the bot¬ 
tom nail with one hand and guides the plumb-bob 
with the other. The nails are now driven in as re¬ 
quired until they are plumb. Care must be taken to 
allow for a fair thickness for the floating coat. This 
should not be more than % inch or less than % inch. 
When working from a wood ground the top dots should 
be kept a little inside the plumb-line to allow for the 
traversing of the cornice screed, because this screed and 
the gathering at the bottom of the cornice are apt to 
throw the wall out of plumb unless cut off or allowed for. 
The dots are completed by laying narrow strips of 
gauged coarse stuff up to and in a vertical line with the 
top and bottom nails; the floating rule is then applied 
and the stuff worked down until flush with the nails. The 
dots should not be wider than the width of the floating 
rule, as the rule when bearing on the nails can only be 
worked with an up-and-down motion, taking in only its 
own width. The length of the dots may vary from 5 
to 7 inches, according to the bearings required for the 
cornice and skirting running mold. Narrow screeds are 
easier, quicker and truer made than wide screeds. The 
latter are apt to have a more or less wavy surface. This 
applies more especially to “laid screeds”—that is 
screeds that are simply laid and ruled off without dots 
or other bearings. 

Lath dots are sometimes used instead of nail dots; they 
are generally used on ceilings and lathed partitions; they 
are not so liable to crack the first coat as nails. They 
are formed by laying a strip of coarse stuff and placing 
thereon a straight lath about 6 inches long and then 
applying a plumb-rule or plumb-bobline as described 
for the nail dots. The lath gives strength and resist¬ 
ance while working the floating rule. After the screeds 


106 


CEMENTS AND CONCRETES 


are finished the laths are taken out and the spaces made 
good. Having finished all the top and bottom dots, the 
top and bottom longitudinal spaces in a line with the 
dots, or, in other words, the screeds are laid with coarse 
stuff. The long floating rule is then applied, bearing on 
the dots and working up and down in a slanting posi¬ 
tion, a plasterer working the rule at each end, and work¬ 
ing together so as to keep the rule square on edge and 
uniformly level. Any surplus stuff is taken off the rule 
and applied to make up any hollow parts in the screed 
or returned to the gauge board, as the case may be. If 
the screeds are extra long another man (sometimes more) 
is required to work at the center of the rule, also clean 
the surplus stuff off, and make up any deficiencies in the 
screed. After the screeds are finished, the nails must be 
extracted to avoid rust discoloring the finishing coat. 
Large surfaces on walls or ceilings should be divided in¬ 
to bays by narrow screeds placed from 6 to 9 feet apart. 
This affords more freedom and regularity for laying and 
ruling off. Gauged coarse stuff is sometimes used for 
the main screed, i. e., the wall and ceiling screeds on 
which the cornice is run. In this case the screeds are 
finished smooth, or so that they only require a very thin 
or filling-up coat of gauged putty for the cornice screeds. 
The splayed edges of screeds, especially gauged screeds, 
should be cut square. A splayed edge being generally 
smooth, affords little or no key, and also being unequal 
in thickness, makes a bad joint for the floating coat. 
If there are any breaks in the room, the screeds must be 
set off square from the side walls, and the projections 
at each angle of the breast made equal. The sides are 
best squared with a large wooden square, and the pro¬ 
jections regulated with a gauge. 

Flanking .—Flanking or filling in consists of laying 


TERMS AND PROCESSES 


107 


the intervening spaces between the screeds with coarse 
stuff, and then ruling the surface straight and flush with 
the screeds, with a floating rule. Two squads of men, two 
or three in each squad, are required for this purpose— 
one squad on the floor, and the other on the scaffold. If 
the height of the room necessitates more than one scaf¬ 
fold, an additional squad is required for each interven¬ 
ing scaffold. In the latter case, the distance between the 
top and bottom screeds would be too great to allow a 
floating rule to be conveniently worked. To overcome this 
difficulty, intermediate screeds must be made at conven¬ 
ient distances. This is done by stretching a chalk-line 
from the top to the bottom screed, and then forming dots 
flush with the line, and laying the screeds as previously 
described. The coarse stuff for flanking should be laid 
upwards, and in an angular line. This plan is not so apt 
to spring the lath or crack the key at the deepest, which 
is the thinnest part of the first coat, as if laid across the 
laths. After a bay is laid, the surface is straightened 
with a floating rule. A plasterer at the top and one at 
the bottom works the rule together uniformly up and 
down with a cutting motion, and keeping it in a slightly 
angular position, so that any surplus stuff may not fall 
on the man below. A rule should not be worked on 
either of its face edges, as by so doing the face becomes 
round and uneven, and conducive of unequal screeds. 
The filling in and ruling off is continued until all the 
walls are completed. When elaborate ceilings have to be 
done, involving the expenditure of much time, the top 
longitudinal screeds are only formed, and the floating of 
the walls left until three or four days before the setting 
can be begun, as the setting coat made from sometimes 
adheres better when the floating coat is partly green, or 
at least not bone dry. As previously mentioned, the 


108 


CEMENTS AND CONCRETES 


whole process of preparing lime plaster and laying it on 
the walls in thin coats, with a considerable space of time 
between the coatings, is conducive to the ultimate hard¬ 
ness of the whole, the lime being first slaked and then 
scoured, all this time being exposed to the carbonic acid 
of the atmosphere. Again, each coat is long exposed to 
the same influence before being covered with the next, 
thus enabling each coat to harden by a natural process 
before the following coat is laid. All things being equal, 
it is advisable to allow each coat to stand as long as pos¬ 
sible before proceeding with the next. Where the wall 
surface is irregular, causing extra thick parts in the 
floating coat, the hollow parts should be rendered or 
“dubbed out,” and the surface scratched before laying 
the floating coat. The dots for the ceiling screeds are 
formed close to the cornice bracket. If there are no 
brackets, the projection of the cornice must be allowed 
for. Lath dots are best for ceiling screeds. They are 
formed at all the angles, and made level all round the 
ceiling. This is done with the aid of a “parallel ceiling 
rule. ’ ’ When all the dots are made, the screeds are fin¬ 
ished, and the surface flanked in as already described. 

For common work, the wall screeds are seldom 
plumbed; but if there are breaks in the room, the ex¬ 
ternal angles, which are more noticeable, should always 
be plumbed. For this class of work two men generally 
work together. Working from the floor upwards, one 
man lays a coat of coarse stuff about 7 inches wide, and 
as high as he can conveniently reach up on both sides of 
the internal angles; his colleague follows on with a float¬ 
ing rule and rules them straight. Before finishing the 
screed, the rule is applied on the portion done, and grad¬ 
ually moved up until one end reaches the cornice line, 
to see if there is a sufficient thickness for the upper part 


TERMS AND PROCESSES 


109 


of the screed. The space between the first-coating and 
the face of the rule shows the thickness available for the 
floating coat. The desired thickness is obtained by lay¬ 
ing more stuff on the screed, or working it down, as 
the case may be. As the floating rule cannot be worked 
close up to the angle, a seam of coarse stuff is formed in 
the angle. 

To allow for shrinkage, and to obtain a firm and 
square angle, the seams are left until all the floating is 
done, after which they are cut off square and flush with 
the floating. This is done with a laying trowel, w )rking 
it on its flat on the firm floating. Any defects in the 
angles are made good when scouring the float¬ 
ing. After the vertical angle screeds are firm, 
horizontal screeds are laid at the highest conven¬ 
ient line, and ruled with a floating rule bearing 
on the vertical screeds. The intervening spaces are then 
flanked in by laying with coarse stuff until flush with 
the screeds. The surface is sometimes ruled fair with a 
floating rule, but more often straightened with a darby. 
After the scaffold is erected, the top portions of the ver¬ 
tical screeds are laid and ruled with a floating rule, 
working it so as to bear on the lower part of the screed 
previously made, which gives a bearing and guide for 
the rule. After allowing for the depth of the cornice 
(if not bracketed), the top horizontal screed is then 
laid and ruled with a floating rule bearing on the ver¬ 
tical screeds. The intervening spaces are then filled in 
with coarse stuff, and ruled in or darbied as previously 
described. The ceiling screeds are made close to the cor¬ 
nice bracket, or (if not bracketed) in a line with the 
outer member of the intended cornice. A screed is first 
made at each of the long sides of the ceiling, and when 
firm the end screeds are laid and ruled, using the long 


iio CEMENTS AND CONCRETES 

screeds as bearings for the floating rule. If the scaffold 
is in position before the floating is commenced, the 
vertical screeds should be formed in one operation. A 
plasterer on the floor lays the lower part of the screed, 
while his partner on the scaffold lays the upper part, 
after which both work with floating rule together in 
their respective positions. Where practical all screeds 
should be finished in one operation. In the event of a 
screed being too long for an ordinary sized rule to take 
in the whole length and work it in one operation, the 
screed can be made straight by working the rule back¬ 
wards and forwards from end to end, testing the 
straightness by applying the rule on various parts of the 
screed. The straightness is further proved by lightly 
stretching a chalk-line from one end to the other end 
of the screed. After the screeds are firm, the main, 
portion of the ceiling is laid with coarse stuff flush with 
the screeds, and then made fair with a darby. 

When floating large surfaces with a darby, it should 
be worked in all directions—longAvise, crosswise, and 
diagonally and finishing with a circular motion. For or¬ 
dinary work a darby is an excellent tool for straighten¬ 
ing large surfaces of floating and setting. It also forms 
a pleasing and easy surface on circular work. For base¬ 
ment and attic rooms a darby properly manipulated will 
form fairly straight screeds as well as the main surfaces. 
When floating large ceiling or wall surfaces for plain 
work, or where it is not necessary that they should be 
perfectly straight, involving time and material, a hol¬ 
low surface is preferable to a round surface. A hol- 
Ijw surface is not so noticeable, and is less objectionable 
to the eye than a round surface. It will be understood 
that a hollow surface, to be pleasing to the eye if noticed, 
should flow gradually and regular from the screeds to 


TERMS AND PROCESSES 


111 


the center of the surface, and not suddenly or in wavy 
parts or patches. 

There is an inferior kind of floating practiced by 
piece-workers, in some districts, for cottage work, and 
even some of the modern jerry-built houses. This is 
executed by floating direct from the walls in one coat. 
The surface is sometimes dry-scoured with a “nail hand 
float, ’ ’ water and proper scouring being unknown in this 
class of so-called plastering. The ceilings are simply 
laid with coarse stuff, and the ridges and smooth sur¬ 
face left by the trowel are worked down and roughened 
by a few rubs with a hand float. This porous and cracked 
shell is finished with setting stuff, gauged with just as 
much plaster as will hold the materials together for the 
time being. The minimum of (or possibly less) trowel¬ 
ling is attempted; a stock brush being found a more 
easy and speedy tool than a trowel for finishing. The 
brush is made to perform the trowelling and brushing 
off in one operation. This shoddy work is unsafe and 
unsanitary, and ought not to be tolerated. 

Scouring Coarse Stuff .—Scouring floated coarse stuff 
is of great importance. It not only consolidates and 
hardens the surface, but also prevents cracks in its own 
body and the subsequent setting coat. For these reasons 
it should be well and sufficiently done. The straightened 
coarse stuff should be allowed to stand to permit of 
shrinkage, evaporation of surface moisture, and a firm 
surface before proceeding with the scouring. Working 
a hand float on a soft surface tends to form “water 
blubs” and hollow parts. When the surface is firm, 
but not dry, the work is fit to scour. This is done by 
the plasterer having a hand float in one hand, and a 
stock brush in the other, with which he sprinkles water 
on the surface, and vigorously applies the float with a 


112 


CEMENTS AND CONCRETES 


rapid circular motion, using a little soft stuff to fill up 
any small holes or inequalities that may have been left 
after the floating rule. Care must be taken that no part 
is missed or less scoured and that the whole surface is 
thoroughly and uniformly scoured. The floating should 
be scoured twice, or for best work three times, and allow¬ 
ing the work to stand from three to five hours, accord¬ 
ing to the state of the atmosphere, between the first and 
second scouring, and one day between the second and 
third scouring. The final scouring should be continued 
until there is little or no moisture left on the surface. 
To obtain the same strength and solidity, all other things 
being equal, coarse stuff composed with a weak lime or 
containing inferior or an excess of sand, or having in¬ 
sufficient hair, or sparsely tempered and used in an 
over-soft condition, requires a greater amount of scour¬ 
ing than coarse stuff which is composed with a strong 
lime, or containing good sand and in due proportion, or 
with an ample quantity of hair, or well tempered, and 
used in a moderately stiff yet plastic condition. Even 
with extra scouring the ultimate strength of inferior 
coarse stuff is remote and doubtful. This simple mat¬ 
ter is a witness to the fact that inferior or insufficient 
materials require more labor than good and sufficient 
materials and that the results are somewhat vague and 
often unsatisfactory. 

Keying .—All plastic materials have great adhesive 
powers, especially to each other. Yet when laying a thin 
body of fine material on a coarse material which has a 
more or less smooth, dry and absorptive surface, such as 
laying setting stuff on floated coarse stuff, the adhesion 
is partly nullified. Portland cement or hydraulic limes, 
which set nearly as soon as laid, require no scouring, and 
being left from the floating rule with an open grained or 


TERMS AND PROCESSES 


113 


rough surface, a natural key is obtained for the final 
coat; but coarse stuff, which only sets or becomes hard 
by evaporation of its moisture, must be scoured to con¬ 
solidate the yielding and soft body. Scouring leaves a 
close-grained and somewhat smooth surface, offering lit¬ 
tle or no key to the setting coat. The floated coat being 
often dry before the setting coat is applied, the suction 
varies greatly; sometimes it is regular, at other times it 
occurs in patches. Sometimes the suction is so excess¬ 
ive that the setting stuff dries up and peels as soon as 
laid, and in other instances the reverse occurs, there 
being no suction at all. In the latter case the setting 
stuff runs downwards in the form of globules or in rivu¬ 
lets. These defects may to a certain extent be corrected 
by laying the setting stuff while the floating is still 
green, or by saturating the surface if the floating is dry. 
Yet to obtain permanent cohesion in the two coats it is 
necessary to key or roughen the surface. This is best 
done by brushing the surface as soon as scoured with a 
stiff whalebone broom or with a wire brush. A common 
plan is to dry scour with a “nail float”—i. e., a hand 
float with the point of a nail projecting about % inch 
beyond the sole of the float. When this method is em¬ 
ployed the float should be worked in a close circular 
motion so as to leave a series of close and irregular in¬ 
dents. The usual and careless way of working the float 
in a wide circular motion leaves the indents too wide 
apart to give a sound and uniform key; indeed, this 
method is of little service. A new tool for keying coarse 
stuff has been recently introduced, which is called a 
“devil” and is similar to the nail float, with the excep¬ 
tion that there are four nail points projecting on the 
sole, one of which is placed about 1^2 inches from each 
angle. The process of keying the coarse stuff with this 


114 


CEMENTS AND CONCRETES 


is termed “devilling.” The work is more speedily and 
better done with the “devil” than with the nail float. 

After the floating is finished the next part of interior 
plaster work is the running of the cornice, and then fin¬ 
ishing the ceiling and walls; but in order to continue 
the methods of setting, the running of the cornice, etc., 
are described in subsequent pages, and the setting and 
other parts of wall work are first described as follows: 

Setting .—Setting is the laying and finishing the final 
coat on floating, termed “finishing,” and “hard'finish” 
or “putty coat.” In the best work great skill and care 
is required to make the surfaces perfectly true and uni¬ 
form in color, smoothness and hardness. The material 
for three-coat work is generally known as “setting 
stuff.” The mode of making has already been de¬ 
scribed. Setting stuff should not be applied until the 
floating is quite firm and nearly dry, to allow for any 
contraction that may take place in the floating. If the 
floating should become quite dry during the time re¬ 
quired for cornice and ceiling work, or where subjected 
to strong winds or a warm atmosphere, it should be well 
wetted a day or two before the setting coat is com¬ 
menced. This prevents the too rapid absorption of mois¬ 
ture from the setting coat and gives a closer union of 
the floating and setting coats. Before wetting copi¬ 
ously, a small portion of the floating should be tested 
with a wet brush to ascertain the degree of suction. In 
some floating there is no suction, or at least there is 
none until the surface has been dampened and the glaze 
and sometimes grease has been washed off. Glaze is 
caused by slightly hydraulic lime, also by insufficient 
scouring. Glaze is more noticeable on first-coating 
which has been left smooth by the laying trowel. Grease 
occurs through friction, also dirt where the float is left 


TERMS AND PROCESSES 


115 


long exposed. These matters of excessive and non¬ 
suction, dry, glazed or greasy surface, either singly or 
in combination, also smooth or unkeyed floating, are the 
cause of cracked or scaly setting, which one sees more or 
less in a plaster career. It is therefore absolutely neces¬ 
sary, to insure perfect cohesion of the two coats, that 
the floated surface should be uniformly keyed, clean and 
damp before the setting coat is layed. Setting consists 
of laying the stuff, scouring, trowelling and brushing the 
surface. 

Laying Setting Stuff .t—The setting stuff is laid in two 
coats, the second following immediately upon the first. 
The laying is best done with a skimming float, which 
leaves the face of the first coat rougher to receive the 
second than if done by a laying trowel, which leaves it 
smooth. The second coat should also be laid with a 
skimming float, which leaves a more open grain for the 
purpose of scouring. When laying setting stuff some 
men take a trowelful or skimming-floatful off the hawk 
and stoop to spread the stuff from bottom to top with 
an upward motion, laying the joint with a return down¬ 
ward motion; but a smart man can take a trowelful or 
floatful of stuff and spread it with a downward motion 
from top to bottom and lay the joint with the return mo¬ 
tion, this saving one stoop in each spread or floatful. 
This is similar to laying setting stuff on a ceiling. A 
man who has a thorough command of the trowel hand 
always lays the stuff in a long even spread outward, 
and lays the joint with the inward return motion. After 
one side of a bay or wall is laid the surface is then 
scoured, trowelled and brushed. 

Scouring Setting Stuff .—The importance of good and 
sufficient scouring of setting stuff with water cannot be 
too strongly insisted upon. The scouring and the water 


116 


CEMENTS AND CONCRETES 


combined consolidate, harden and render the surface of 
a uniform texture and evenness. The work must be well 
and thoroughly scoured, twice with water and an ordi¬ 
nary hand float and finally with a crcss-grained float. 
The hand flcat is worked with a short and rapid circular 
motion and sprinkling water uniformly with a stock 
brush until the surface is uniform in moisture and tex¬ 
ture. After a rest to allow the stuff to shrink the scouring 
is repeated, and then it is ready for the final scouring. 
This is best done with a cross-grained hand float, which, 
having sharp square edges, cuts off all ridges and leaves 
the setting with a uniform and even surface that cannot 
be so quickly or as well done with an ordinary hand float. 
Water is more sparingly used for the final scouring, 
using only as much as will moisten the surface and allow 
the float to work freely. The scouring is continued until 
a dense, even and close-grained surface is obtained for 
the trowelling. 

Trowelling and Brushing Setting Stuff .—Trowelling 
setting stuff is best done by the use of a half worn 
trowel (commonly called a 4 ‘polisher”), the edges of 
which should be perfectly straight and parallel. Some 
men use an old and worn trowel with the point narrower 
than the heel. This shaped trowel should never be used 
for high class work, since, not being parallel, the press¬ 
ure when trowelling is not equal, and the heel or widest 
part is apt to score the surface of the setting. The 
trowel and water should be perfectly clean to prevent 
any discoloration. The trowelling should be done by 
one man following up the other, who is finishing the final 
scouring. This is done by the plasterer having a polish¬ 
ing trowel in one hand and a stock brush in the other, 
with which he sprinkles water on the surface and works 
the trowel in long and vigorous strokes, first downwards 


TERMS AND PROCESSES 


117 


and upwards, and then crossways or diagonally. This is 
repeated, using the water more sparingly and finishing 
or “trowelling off” with an up-and-down motion and 
leaving the surface free from “fat” or “glut.” The 
work is then brushed with a wet stock brush, first up and 
down, then crossways, afterwards up and down a sec¬ 
ond time. The brush is then semi-dried by violent shak¬ 
ing, or rubbing on a clean board, the work again being 
brushed as before and finished perpendicular. 

General Remarks on Setting .—When the work is re¬ 
quired for painting the setting stuff is laid on the form 
of screeds, and when firm the intervening spaces are 
laid flush with the screeds and the whole surface ruled 
fair with a floating rule. Should there be any hollow 
or soft places (the latter being liable to shrink), they are 
filled in with more setting stuff and ruled over again. 
This is repeated until the whole surface is true and uni¬ 
form in thickness and firmness. The whole surface can 
be scoured, trowelled and brushed in one operation. 
This method has the advantage of saving joints at the 
connections between the height a man can lay and finish 
the setting stuff. 

Joints, unless carefully done, are an eyesore, as they 
are liable to be more or less discolored and uneven on 
the surface. The best method for making joints and 
setting stuff, where it is inconvenient to lay and finish 
the whole surface in one operation, is to leave the edge 
of the joint untrowelled, leaving a scoured margin so 
that the adjoining portion can be laid and scoured with¬ 
out spoiling the trowelling of the first portion. For in¬ 
stance, when setting the walls of a room one scaffold 
high the top parts are laid down to the level of the 
scaffold, or as far as convenient, and the surface scoured 
and trowelled. The latter must not extend to the end 


118 


CEMENTS AND CONCRETES 


of the scoured part, so as to leave an untrowelled margin 
about 4 or 5 inches wide until the scaffold is struck. 
After the scaffold is removed the lower portions of the 
walls are laid flush with the untrowelled margin, and 
then the surface is scoured as before, always going well 
over the joint. The surface is then finally scoured with 
a cross-grained float, taking care to moisten and rescour 
the untrowelled margin to render the whole of the 
scoured surface equal in texture and moisture for trowel¬ 
ling. The surface is then trowelled and brushed as al¬ 
ready described, taking care to go over the trowelled and 
brushed joint. By this method no joints are visible, and 
an even surface is obtained. When the suction is slow 
or irregular, causing the setting stuff to run or be soft 
in places, float the surface with a darby until sufficiently 
fair and firm to be scoured. A darby is very useful for 
forming a fair surface on setting stuff before scouring 
and trowelling. It forms the next best surface to a 
ruled surface. A darbied surface is better and truer 
than a laid surface. 

No more setting stuff hould be laid than can be con¬ 
veniently finished in one operation or day. Where prac¬ 
tical, one side of a wall should be finished in one piece, 
and sufficient men should be employed thereon. If the 
room is not too high, one man or set of men may do the 
upper part, while another man or set of men does the 
lower part. The joints are then made while the setting 
stuff is green. In high rooms, several sets of men work 
together on different scaffolds, each about 6 ft. 2 in. 
apart. All angles should be ruled in with a long float¬ 
ing rule. External angles are sometimes formed by 
nailing a running rule or a straight edged plumb on one 
side of the wall, to act as a guide, but external angles are 
generally finished with a run cement bead or an arris. 


TERMS AND PROCESSES 


119 


An average thickness of % inch of setting coat when 
finished gives the best result. It should not exceed 3-16 
inch, or be less than 1-16 inch in thickness. If too thick, 
it is liable to crack and flake; if too thin, it- is liable to 
peel. Where extra strength, and cohesion between the 
floating and setting coats is desirable, the first coat of the 
setting has a little white hair mixed with it. White hair 
does not show through the last coat. 

Common Setting .—Common setting for wall and ceil¬ 
ings is generally used for second-class work. It is done 
by laying one coat of setting stuff with a skimming float, 
and scouring and trowelling once and brushing twice. 
Where the floating cracks by contraction, or by using in¬ 
sufficient hair in the coarse stuff, or by want of scouring, 
or where the work is green, the cracks are knocked in 
with a hammer. The indents are then filled up with 
gauged setting stuff, and the whole surface laid with a 
coat of this material, on which a coat of neat setting stuff 
is laid, scoured, trowelled, and brushed in the usual 
way. 

Skimming .—Skimming is an inferior class of setting, 
and is only used for the most common work. It is done 
by laying a coat of fast-setting stuff with a laying trowel. 
The stuff is skimmed over the floating as thin as possible, 
using only as much stuff as will whiten and smooth the 
floating surface. It is trowelled once, and brushed as 
soon as laid. 

Colored Setting .—A beautiful color and brilliant finish 
for walls is obtained by mixing an equal quantity of 
sifted marble dust with setting stuff and using this 
“marble setting stuff” as a final coat. Ordinary setting 
stuff is greatly improved by substituting a part of mar¬ 
ble, or alabaster, or gypsum dust, equal in bulk to half 
the sand generally used. The marble dust should be as 


120 


CEMENTS AND CONCRETES 


coarse as the sand. Crushed spar is sometimes used in 
setting stuff to obtain a sparkling surface. Barytes, sco¬ 
ria, and slag are sometimes used as a substitute for sand, 
for coloring and hardening purposes. Brick dust is also 
used for coloring, and weather and heat resisting pur¬ 
poses. Ground glass as used by Indian plasterers gives 
a sparkling surface. Setting stuff may also be colored 
with the same materials as described for colored stucco. 
Where marble dust or any of the above materials are 
used, they should not be added until the setting stuff is 
required for immediate use. They should not be used 
until perfect amalgamation has ensued. 

Gauged Setting .—Gauged setting is used where the 
floating is soft, or where the work is required for imme¬ 
diate use, and also for finishing gauged floating. This 
is performed by one man laying the gauged stuff with 
a skimming float, while his partner follows up with a 
darby to lay the surface fair. Another batch of setting 
stuff is then gauged, and one man lays a thin coat with 
a trowel, and the other man follows immediately and 
trowels the work before it is set. The surface is finished 
by brushing with a semi-wet brush. Gauged setting 
should never be scoured unless the size water is used in 
the gauge to delay the setting, as it will kill the plaster 
and render the stuff useless. Even if size water is used, 
the scouring must be slightly and quickly done. If a 
gauged surface is desirable, a fair and hard surface is 
obtained by simply darbying and trowelling as soon as 
laid. 

Gauged Putty Set. i—Ceilings are sometimes set with 
gauged putty. This is best done by first laying a 
“scratch coat” of gauged putty with a skimming float, 
and then passing a hand float over the surface (before 
the stuff is set) to lay down any ridges, and make the 


TERMS AND PROCESSES 


121 


surface more even to receive the second coat. This is 
laid with a laying trowel, and then trowelled before the 
stuff is set. The surface is then finished with a semi-wet 
brush. Trowelling after the stuff is set, or even has 
begun to set, kills the stuff, and causes it to peel. A 
little washed sand added to the putty makes a stronger 
surface, and not so apt to peel. 

Putty Set .—In some districts common ceilings are fin¬ 
ished with a thin coat of neat lime putty; but unless the 
putty is made from grey limestone, or is of a hydraulic 
nature, the work is more or less weak, and in most cases 
practically useless. 

Internal Angles .—The setting coat of internal angles 
on room walls should be ruled fair and then cleaned out 
with a feather-edged rule. Before scouring the setting 
stuff, the angles should be squared and made straight 
with an angle float. The angle float is a tool now unfor¬ 
tunately seldom used, but it is the best tool for making 
a true angle. In the absence of an angle float, the angle 
should be made fair and square with a cross-grained 
float, and finished with a margin trowel or the heel of a 
laying trowel. The common way, used in some districts, 
of finishing an angle with a gauging or pointed trowel, 
should not be encouraged, as it is impossible to make a 
true angle with a tool of this shape. 

External Angles .—The external angles of room walls 
and windows are generally finished with a bead, but in 
some instances with a plain arris, splay, or small mould¬ 
ing. They are formed with Parian or other white 
cement, and usually run after the floating is done. The 
floating should be cut square on each side, and down to 
the brick or lath work. After dusting and wetting the 
foundation, a running rule is fixed on one side, and then 
the bead or arris is run. The run edges form bearings 


122 


CEMENTS AND CONCRETES 


lor the setting coat. A run arris is more speedily done 
and truer than a ruled and trowelled arris. In some 
districts wooden beads are used for external angles. The 
floating is cut down at each side of the bead, to allow the 
quirks to be formed when the setting coat is laid. When 
the setting coat is trowelled, the quirks are formed by 
applying a large-headed nail on the bead, and drawing 
it up and down to cut the stuff out. They are then fin¬ 
ished by working a laying trowel up and down until 
smooth and true, and afterwards wet-brushed. The 
head quirks are sometimes cut out by aid of a wooden 
template, also by laying a straight edge on the work as 
a guide for cutting the stuff out. They are then finished 
with a trowel and brush, as already described. 

Shirtings .—Skirtings or base, are. sometimes formed 
in wood, but are often formed in cement. Cement skirt¬ 
ings are far more sanitary than wood skirtings, as the 
former connects the wall and the floor in one solid fire- 
resisting and vermin-proof body, whereas wood skirtings, 
owing to their nature and construction, afford a ready 
harbor for vermin, and offer but little or no resistance 
to damp and fire—indeed, their hollow formation pre¬ 
sents a vent in the case of fire. Parian or other white 
cement is generally used where a fine finish is desirable, 
and Portland cement where the work is exposed to wet 
and hard wear. Skirtings are generally run by first 
roughing out the plinth by aid of a gauge rule bearing 
on the floating, and then forming a running screed, and 
fixing a running rule on the plinth. The skirting mould¬ 
ing is then run in the usual way, after which the running 
rules are taken off, and the plinth set. The mould plate 
should be cut to form about 1 inch of the top part of the 
plinth, to form the arris, and a bearing when setting the 
plinth. The annexed illustration (No. 4) shows the 


TERMS AND PROCESSES 


123 


method of forming the core and plinth, and running 
the moulding. Fig. 1 shows the gauge rule (G) in posi¬ 
tion to form the core (C). The gauge rule is from 3 
feet to 4 feet in length. The plinth is formed by first 
roughing out with gauged stuff, and then drawing the 
gauge rule along the floating to form the core, and a 
fair surface for the running screed. Fig. 2 shows a sec¬ 
tion to form the core (C). The gauge rule is from 3 
(R) fixed on the plinth or core (C). 



t-Skirting Formation. 
NO. 4. 


Two-Coat Work .—This is a cheap method of plaster¬ 
ing, and only used for common work, such as the walls 
of factories, warehouses, &c. It is performed by laying 
one coat of coarse stuff and then forming the surface 
fair with a darby, after which it is scoured once. It is 
then finished by laying a thin coat of setting stuff over 
the surface, and then trowelling once and brushing twice 
wet and once semi-wet. 

One-and-a-Half-Coat Work .—This is sometimes termed 
“coat-and-half work.” It is a species of two-coat work 
—in fact, it is so termed in some districts. It is done by 























124 


CEMENTS AND CONCRETES 


first laying a coat of coarse stuff fair, and then scratch¬ 
ing the surface with a coarse broom, after which a thin 
coat of extra fat coarse stuff is laid, straightened with a 
darby, and then trowelled and brushed. The second coat 
must be laid while the first is green. This permits the 
two coats to amalgamate better, and the surface to be 
more easily worked and finished. 

Stucco .—Stucco is an Italian term usually applied in 
Italy to a superior species of external plastering. Ac¬ 
cording to Vasari, Primaticcio “did the first stucchi ever 
executed in France, and also the first frescos.” In the 
United States stucco is a somewhat indefinite term, used 
loosely for various plastic mixtures in whose composi¬ 
tion lime, plaster, or cements enter. Hydraulic lime 
was formerly used for external stucco. Roman cement 
was extensively used for stucco fronts during the first 
half of the present century. Selenitic lime has some¬ 
times been used for a similar purpose. These materials 
are now entirely superseded by Portland cement. The 
adoption in England of stucco externally to give brick 
houses the appearance of stone is due to Robert Adam. 
Its plastic nature enables it to adapt itself to most archi¬ 
tectural purposes with very considerable decorative ef¬ 
fects. The more general use of stone and the improve¬ 
ments in terra cotta have so greatly decreased the use of 
stucco for fronts, that stucco has become a synonym for 
a sham, and its real usefulness for certain works and 
places has been greatly overlooked. When properly pre¬ 
pared and manipulated it makes excellent work, and in 
the near future a large use may be predicted for its use. 

Old Stucco .—It has already been shown that stucco 
was largely employed by the ancients for plain and dec¬ 
orative purposes. The temple of Apollo at Delos, and 
even the first Parthenon under the iEgis of Pallas her- 


TERMS AND PROCESSES 


125 


self, were plastered with stucco. Vitruvius in his sev¬ 
enth book mentions stucco under the name of opus al¬ 
ii arium, sometimes written album opus. Tectorium opus 
(from tector, a plasterer) was a name given by the Ro¬ 
mans to a mortar used for plastering. According to 
Vitruvius, Palladius, and Pliny, there seems to have been 
a difference between tectorium opus and that called al- 
barium or album opus. Vitruvius says tectorium was 
composed of three ccats of lime and sand, and three of 
lime and marble. According to Winckelman, the united 
thickness of these coats was not more than one inch. 
The first coat was of common, but old, lime and sand, 
and when it was nearly dry a second coat of lime was 
laid, and on this drying a third coat of fine lime was laid 
and made fair. The work was then laid with another 
two coats of lime and marble, and finished with a coat 
of fine marble powder. The marble mortar was fre¬ 
quently beaten to redder it tough and yet plastic, and 
it was judged fit for use when it would no longer stick 
to the trowel. When the lime mortar was dry, the mar¬ 
ble mortar was laid, each successive coat of marble mor¬ 
tar being laid before the preceding one was quite dry. 
The first coat of marble mortar w T as composed of coarse 
ground marble and old lime, the second of fine ground 
marble and lime, the finishing coat being neat marble 
ground to a fine powder, and laid before the second coat 
was dry, and worked with a wood float until the surface 
was consolidated and straight. When dry it was pol¬ 
ished with lime and chalk or with marble until like mar¬ 
ble itself. Old stucco has been found so hard and highly 
polished that it has been used for looking-glasses and 
tables. In time it became hard and not liable to crack, 
and formed an excellent ground for the painting with 
which the Greeks and Romans decorated the walls of 


126 


CEMENTS AND CONCRETES 


their houses. According to Vitruvius, this painted plas¬ 
ter could be detached without fear of injury, and de¬ 
tached slabs were carried to Italy and inserted in the 
walls of Roman houses. To prevent the cracking of the 
work done on wood, it was strengthened by two layers 
of reeds, one layer crossing the other at right angles. 
To insure dryness, and allow the plaster to attain its 
proper hardness, the walls were perforated at suitable 
places. The tectorium was then decorated with brilliant 
colors, which were applied on the last coat while it was 
fresh; and to heighten the brilliancy and endurance of 
the colors the surface was rubbed over with wax and 
pure oil. When marble was used with lime in place of 
sand it was termed martmoratum. The alburium or 
album opus was what we term plaster or stucco. The 
Greeks named tectorium and alburium, koniama and 
kalachrisis. 

Slabs of tectorium from the walls of Pompeii and Her¬ 
culaneum are now in the Museum of Portici, and speci¬ 
mens are also in the South Kensington Museum. In the 
Museum of Practical Geology, London, there are several 
pieces of old plaster, taken from the ruins of Pompeii, 
some of which show that the decorative colors were not 
applied a la fresco, but subsequent to the polishing. 
Stucco and plaster are really two very different things. 
Stucco has for its base carbonate of lime, generally burnt 
limestone or chalk, with which putty lime and coarse 
stuff is mixed with sand, &c., and used for plastering 
walls and ceilings. Plaster has for its base sulphate of 
lime, being made from gypsum, and is used for cast 
work and gauging with lime putty, &c. The best kinds 
of stucco will resist the action of weather, and can be 
washed. Plaster, unless specially prepared or indurated, 
perishes by exposure, at least in our climate, and cannot 


TERMS AND PROCESSES 


1 07 

1 - 9 

be washed. Stucco is a superior kind of mortar, and it 
may be .used for plastering or for modelling. The ad¬ 
mixture of various materials with lime and with plaster 
to form stucco is referred to by many ancient writers. 
Pliny mentions fig juice as being mixed with stucco. 
The Egyptians mixed mud from the Nile with plaster 
for some of their work. Elm bark and hot barley water 
was mixed with the stucco for Justinian’s Church of the 
Baptist, Constantinople. We find bullocks’ blood em¬ 
ployed for this purpose as well in mortar for Rochester 
Cathedral in the latter part of the ninth century. Bishop 
Gundulph (1077-1108) is stated to have mixed blood 
with lime to make it hard. Hot wax mixed with lime 
was used at Rockingham Castle in 1280. White of eggs 
and strong wort of salt were mixed with lime used for 
Queen Eleanor’s Cross at Charing Cross in 1300. Pitch 
and wax were mixed with the lime used for Edward 
II.’s works at Westminster in 1324. Mediaeval build¬ 
ers habitually used beer, eggs, milk, sugar, gluten, &c., 
for mixing with mortar for cathedrals. Frequent en¬ 
tries found in the archives prove this. One reads, “For 
beer to mix with the mortar. ’ ’ Bess of Hardwicke’s ma¬ 
sons used beer in their mortar, having to melt it in the 
cold winter of her death. Old plaster is found to have 
rye straw mixed with it for binding, and was very strong. 
A brown substance somewhat like plaster, but full of 
fibre, was in use in the sixteenth century. The accounts 
for the repairs of the steeple of Newark Church in 1571 
contain an entry, “6 strike of malt to make mortar to 
blend with ye lyme and temper the same, and 350 eggs 
to mix with it.” During the building of the Duke of 
Devonshire’s house at Chiswick, the exterior of which 
was plastered with stucco, the surrounding district was 
impoverished for eggs and butter-milk to mix with the 


128 


CEMENTS AND CONCRETES 


stucco. Peter le Neve’s mention of rye dough stands 
not alone, as Sir Christopher Wren’s ‘‘Parentalia” 
(1750) records the use of “marble meal” as the old and 
still the modern way of stucco work in Italy. “Marble 
meal” simply meant marble dust ground as fine as meal. 
This dust was used fo^ fine work. Sugar and the gluten 
of rice are used in Ceylon and India. The Chinese use 
a rich unctuous earth in combination with lime. In some 
parts of France urine was used with plaster in the six¬ 
teenth century. Nearly all these admixtures are to re¬ 
tard the setting, to allow more time for the manipulation 
of the stuccos. Some are to accelerate the setting, and 
some are to increase their ultimate hardness. 

Many of the ancient buildings in various parts of the 
universe, which were built of mud, clay, or sun-dried 
bricks, had their surfaces decorated with hand-wrought 
stucco. During explorations in Peru, South America, 
Dr. Le Plongeon found some interesting specimens of 
ancient plaster work in a number of the ruins of the 
early Peruvian houses and cities, which date back to re¬ 
mote antiquity. At Chenni Concha he found the frag¬ 
ments of some ancient ornamental stucco on the adobe 
(or clay-built) walls, covered with bas-relief decorative 
designs, while the material is after many centuries still 
in good preservation. The design and the execution are 
of considerable merit, and it seems wonderful that a 
people ordinarily held to be but little better than savages 
could have conceived ornamentations so aesthetic, and 
have executed them with such high technical ability. 

Cav. M. Geggenheim, who has had much stucco work 
done in the Palazzo Papadopoli and elsewhere, gives the 
following formula for the stucco duro which is still used 
in Venice: It is old stone lime, slaked for three years 
at least, mixed with Carrara marble dust, ground as fine 


TERMS AND PROCESSES 


129 


as flour, into the consistency of paste. This of course 
is for the finishing coat, the rough modelling being ex¬ 
ecuted with a coarser material. 

There are four kinds of so-called stuccos which are 
used in this country. They are known as common, rough, 
bastard, and trowelled. The methods of working these 
species of plastering are embodied in the description of 
three-coat work—in fact the only difference between 
these stuccos and three-coat work lies in the setting coat, 
the first-coating and floating being the same for all. 
Some of the above terms are now only used by work¬ 
men, and the use of stuccos is to a great extent super¬ 
seded by Portland cement for exterior work, and Parian 
and other white cements for interior work. The follow¬ 
ing is a summary of the materials and methods used for 
the various stuccos. 

Common Stucco .—Common stucco was principally 
used for exterior work. It is composed of 3 parts of 
coarse sharp sand to 1 of hydraulic or grey lime, to which 
a small portion of hair is added. It is laid in a similar 
way to ordinary rendering in one coat, and the surface 
finished with a hand float. 

Rough Stucco .—This is generally used for plastering 
churches, corridors, and entrance halls to imitate stone. 
The work is floated with ordinary coarse stuff, and then 
set with stuff composed of 3 parts of washed sharp sand 
and 2 of grey lime putty, not chalk. This is laid with 
a trowel, and then ruled in with a straight edge until 
the surface is full and fair. After this it is scoured 
with an ordinary hand float, and finished with a * 4 felt 
float,” not to raise the grit, but to keep it down. The 
felt float is an ordinary hand float with an unplaned 
sole, on which a felt sole, about % inch thick, is fixed 
with gauged plaster. This tool before using generally 


130 


CEMENTS AND CONCRETES 


requires to be rubbed on a straight stone to obtain a uni¬ 
form face. Great care must be exercised when laying 
and finishing the surface, so that no joints are shown, 
or else they will never dry ont. When wanted to repre¬ 
sent ashlar masonry, the surface is set out with lines to 
the size of the required stones, and then the lines are 
indented to form the joints with a jointer or the ring 
end of a key. The grain of the stone can be better imi¬ 
tated by patting the surface with the hand float as a 
finish. The staining of stucco to represent the color of 
stone is done by diluting sulphuric acid (oil of vitriol) 
with water, and mixing with it the liquid ochres and 
other colors to the required tints. The setting stuff may 
also be mixed with the ochres before using. A small por¬ 
tion of the colored stuff should be dried to ascertain the 
tints before laying the whole surface. 

Bastard Stucco is somewhat better in quality than or¬ 
dinary setting. The final coat is composed of 2% parts 
of washed sharp sand and 2 parts of chalk lime putty. 
It is laid in two coats with a skimming float, scoured up 
once and then trowelled off and brushed. 

Trowelled Stucco is generally used for work that has 
to be subsequently painted. The stuff for the finishing 
coat is composed of from 2 y 2 to 3 parts of washed sharp 
sand to 2 parts of chalk lime putty. The sand is not so 
fine as that used for ordinary setting, being washed 
through a sieve having about 12 mesh to the inch. The 
stuff is laid on, and then traversed with a floating rule 
in all directions, up and down, across and diagonally. 
The surface is then scoured up without water, and after 
a rest to admit of shrinkage, the surface is scoured up 
three times with water; the trowel to immediately follow 
the third scouring up. This trowelling is continued 
until the work becomes so hard that no impression can 


TERMS AND PROCESSES 


131 


be made on the surface; it is then brushed off with a 
soft damp brush (not wet), first horizontally, then diag¬ 
onally, and finally perpendicularly, leaving a brilliant 
face. When dry, the gloss goes off, and leaves a fine 
surface for paint. 

Colored Stucco .—The Italians execute lime stuccos in 
colors, mixing in the lime various oxides—i. e., blacks 
are obtained by using forge ashes containing particles of 
iron; pearl greys are made by mixing ashes with the 
marble; greens are obtained by using green enamel, with 
a large proportion of marble powder, worked up with 
lime-water; browns by mixing ashes with the lime and 
marble in proportions varying with the tints desired; 
reds by using litharge, or the red oxide of lead; blues 
by mixing 2 parts of marble powder and 1 of lime, and 
y 2 of oxide, or carbonate of copper. Stucco may also 
be colored with the same materials as described for 
colored setting, also for sgraffito and concrete. 

Method of Working Keen’s, Parian, and Martin’s 
Cements .—When describing the technique or practical 
manipulation of Parian and the other white cements 
which have been invented in the nineteenth century, it 
is only natural that one should feel animated by a pecu¬ 
liar pleasure, because in these cements, our industry, 
aided by modern science, has, as far as is known, 
equalled, if not excelled, anything of the kind produced 
by the ancients, tested by any experiment, whether for 
strength, solidity, or durability. With these a great sav¬ 
ing in time can be effected, as work can be begun and 
finished in one operation, without waiting for the differ¬ 
ent coats to dry, as in ordinary lime plastering. For 
sanitary purposes they are unequalled. This, combined 
with their chemical properties, which enables them to be 
painted, papered, or distempered as soon as finished, 


132 


CEMENTS AND CONCRETES 


renders them the most valuable of all plastering materials 
in this go-ahead age. They are free-working, sanitary, 
durable, and practically fireproof. They are the very 
best materials for plastering walls, dadoes, or in similar 
exposed positions. For skirtings they are invaluable, 
as they offer an effectual resistance to fire, vermin, and 
dust. When properly manipulated, they can be worked 
to a porcelain-like surface. They are nearly perfection, 
and constitute perfect plasters for mcst interior work. 
Their only drawback is that they will not resist the ef¬ 
fects of moisture. It is therefore imperative that damp 
walls should be floated with Portland cement, where 
a white cement finish is desirable. By the aid of the 
hard and sanitary white cements plastering has become 
a tangible reality, instead of a comparative makeshift, 
which it has hitherto been. The object aimed at in the 
invention of white cements for internal use is to pro¬ 
duce a material of which plaster is the base, which shall 
set sufficiently slow to be easily manipulated, become 
dense, hard, non-porous, and may be painted as soon as 
finished. Before the introduction of these cements, all 
making good, as it is technically called (i. e., patching 
holes in old plaster work), used to be done with neat 
plaster, plaster and sand, or lime gauged with plaster. 
Keen’s was first introduced, then Parian, and lastly 
Martin’s. Parian being most in demand, claims priority 
in description. Parian and other white cements are uni¬ 
formly reliable in quality, but through the rapacity of 
some contractors the cements are often adulterated with 
plaster to lower the cost, and hasten their setting. This 
adulteration causes the cement to swell, and in many in¬ 
stances to peel or fall off. Even if it does adhere, it 
never attains its due hardness, and thus is no better than 
ordinary plaster. Unfortunately adulteration brings 


TERMS AND PROCESSES 


133 


discredit on the cement and the trade. The only remedy 
is proper supervision by a plasterer who possesses a thor¬ 
ough knowledge of plastic materials and the methods of 
using them. If plasterers were awarded certificates of 
competency, adulteration would be prevented, and good 
work ensured. Honest employers would find this bene¬ 
ficial, for scampers can only thrive where there is a lack 
of knowledge of the technique peculiar to plastering, 
and which only plasterers of experience really possess. 

In using Parian cement on lath-work, exceptional care 
must be observed that all the lath nails be galvanized, 
or painted over, or coated with shellac, to prevent rust. 
For this same reason all nails used for plumbing and 
levelling purposes must be extracted after the screeds 
are set. For first-coating and floating ceilings with this 
material, the proportions for best work are 1 part of 
cement to 2 of clean sharp sand, adding about the same 
quantity of hair as for lime plaster. Walls are generally 
floated with Portland cement in the proportion of 1 part 
of cement to 3 of sand, and finished with neat Parian. 
This system is adopted as a matter of economy, as Port¬ 
land cement is cheaper than Parian; and where time is 
no particular object, makes equally as good work. For 
walls intended to be painted or polished immediately, it 
is necessary to mix the materials in the same proportion 
as for ceilings, with the difference that more sand may 
be used—say 2 parts of cement to 5 of sand. The rea¬ 
son for this is, that when floated with Portland, and 
finished with Parian an efflorescence invariably appears 
on the finished surface, and until it has time to dry out, 
it is inimical to successful painting or polishing. Gaug¬ 
ing is an important point; it must be carefully and 
quickly done to insure success and obtain the full 
strength of the cement. For first-coating or floating 


134 


CEMENTS AND CONCRETES 


ceilings, empty a sackful, or half a sack according to 
requirements, in a clean banker; then add the sand in 
the proportions already given, and thoroughly mix the 
cement and sand while yet dry; then form a ring, and 
. pour in the water, taking care not to pour in too much, 
as it must be gauged, and used as stiff as practicable. 
There will be no difficulty in thus using it, as it will take 
some hours to set, according to the season of the year 
(quicker in summer than in winter). When the water 
is in, add the hair (which must previously be well beaten 
and soaked), and gauge the whole mass together. Then 
begin the first coating, scratch it in the usual manner, 
and so on, until the whole ceiling is first-coated. It 
should stand for twenty hours before starting to float. 
Hair is generally omitted for common work, or where 
the laths are close. 

Parian cement ceilings should be dead level, and have 
a uniform and straight surface; therefore the screeds 
should be levelled, made narrow, and the sides cut square, 
and when firm the whole ceiling should be ruled in with 
a floating rule, sufficiently long to reach from screed to 
screed. The floating stuff is gauged moderately stiff, 
and laid diagonally across the line of laths, so as not to 
spring the lath-work, or disturb the key of the first-coat¬ 
ing. After the ceiling has been laid, the floating rule is 
applied, a man holding each end (and one at the center 
if extra long). It is then drawn gently and steadily 
along, filling up hollow places, until the whole surface 
is straight and true. When the surface is firm, it is 
brushed with a coarse broom to form a key for the finish¬ 
ing coat. If there is a Parian cement cornice to be run, 
the usual mode for plaster and putty is adopted for the 
running rules. The screeds should be made sufficiently 
smooth to run on, without forming an extra thickness oi 


TERMS AND PROCESSES 


135 


traversing screed. The cornice is roughed out with the 
same kind of material as used for the floating, employ¬ 
ing a muffled running mould for running the rough stuff. 
It may not be practical 10 rough out all the cornice at 
once, as this stuff does not set quick, therefore it may be 
necessary to leave it for a time until the stuff stiffens. 
No definite directions can be laid down in this matter, as 
the suction is greater in some seasons and rooms than in 
others. A little extra hair, also extra stiff gauging, is of 
service to make the stuff cling together, thus allowing 
the work to be roughed out sooner. The running moulds 
must be made of strong zinc or copper (no iron to be 
used on any account). Where the work is in cornices, 
skirtings, achitraves, &c., the mould should he muf¬ 
fled with a zinc or copper plate. If there is only a small 
quantity to be run, a plaster muffle may suffice. After 
the cornice is roughed out, it is finished with neat Parian, 
and then the mitres formed in the usual way. 

In preparing to finish a large space (ceilings or walls) 
it is absolutely necessary that no more should be laid 
than can be finished the same day, therefore as many 
men should be put on the job as will accomplish that 
object, as no sign of a joint should be shown on the sur¬ 
face.’ In the case of large or high walls, the scaffold 
should be so arranged that the men can work the whole 
wall from the cornice down to the skirting in one opera¬ 
tion. If a wooden skirting has to be subsequently fixed, 
one end of the rule bears on the fixing grounds; but if a 
Parian skirting or base is specified, it is generally run 
before the walls are finished, and allowed to get thor¬ 
oughly hard, so as to bear the end of the rule used for 
the finishing coat. The lower end of the rule is cut to 
fit the upper member of the skirting. Another way is 
to nail a board onto the end of the rule, so that it bears 


136 


CEMENTS AND CONCRETES 


well on the plain plinth and clears the members of the 
skirting. The cornice screed must be keyed with a drag 
before the finishing coat is laid. For large cornices it 
is often desirable to traverse the running screeds. In 
this case they must be cut down to the floating, leaving 
only the margin formed by the running mould. This 
margin forms a bearing for the top end of the rule. In 
some instances a special margin or bearing is cut at the 
outer members of running moulds for cornices and skirt¬ 
ings, and when run they form a bearing for the floating 
rules. 

When ready for the finishing coat, empty as much as 
required of neat Parian cement into a clean banker, and 
gauge it smooth and stiff; then soften it down to the 
desired consistency, always bearing in mind not to make 
it too soft, as sloppy stuff for any purpose is ever to 
be avoided. The gauging should be so arranged that 
when one batch is in use another one is ready, which 
prevents delay in laying the whole space, thereby ensur¬ 
ing similarity of texture and results. The thickness of 
the finishing coat should not exceed % inch. When 
there are about a dozen yards laid, two men must follow 
on and rule the surface fair from screed to screed on 
ceilings, and top and bottom on walls. The greatest pos¬ 
sible care must be observed that the whole surface is 
ruled in fair and uniform, otherwise the surface will be 
imperfect. 

White cements, owing to the suction of the walls or 
ceilings, have a tendency to shrink more or less, accord¬ 
ing to the stiffness of the gauge and the section, there¬ 
fore they must be ruled in twice. When the coat already 
laid is firm, then some more cement, gauged softer than 
the first, should be laid thinly all over, and ruled as care¬ 
fully as before. Having done this the whole surface is 


TERMS AND PROCESSES 


137 


nearly ready for scouring. It is allowed to stand for an 
hour or two, or until quite firm. If scouring is at¬ 
tempted before, it will work into hollows, and a bad job 
will be the result. If the finger cannot make an im¬ 
pression upon it easily, it is sufficiently firm, and then 
all hands begin to scour the work, using very little water, 
and working the hand float with a circular motion. The 
hand float must not be worked long on one spot, but kept 
moving over all the surface within reach, and working 
back again until the whole surface has an even grain or 
texture. The whole work must be scoured twice to bring 
it up to a fine solid surface. When there is about half 
of the wall scoured, two or more plasterers can continue 
the scouring, and the remainder of the men go back and 
start the trowelling. This must be done with good long 
strokes, using very little water, and taking care not to 
dent the surface with the trowel. After the men have 
finished the scouring, they come back and start at the 
beginning with the second “trowelling off” or final 
trowelling. This is done both vertically and horizon¬ 
tally, and when the work begins to harden, the trowel is 
laid on the near edge and worked with a cutting motion 
downwards. This is repeated all over the work until 
every particle of glut or “ fat ” is cleared off the surface. 
If the work has to be polished, the cutting action with 
the trowel must be followed with a 9-inch joint rule and 
a damp brush, but the work must be hard before this 
last can be attempted. Work carried out on the above 
plan will reflect credit on the material and the workers. 
The same methods apply equally to Keen’s and Martin’s. 
Martin’s is preferred by some plasterers for running 
cornices because it sets quicker than Keen’s. For plain 
surfaces, such as w^alls and ceilings, it sets too quick, 
and has to be “killed” (that is working the stuff again 


138 


CEMENTS AND CONCRETES 


and again with water until the initial set is stopped or 
“dead”) before it can be conveniently used. Although 
it finally sets fairly hard, it never attains the same de¬ 
gree of hardness as Keen’s or Parian. 

Several other white cements and plasters have been 
introduced during the last two decades. They will be 
noticed later on. 

White Cement Efflorescence .—For work that has to 
be painted, care must be exercised in the selection and 
manipulation of the materials used for the plaster work, 
so as to avoid as far as possible subsequent efflorescence. 
In the manufacture of Keen’s, Parian, and Martin’s 
cements, Keen’s original process is doubtless the best. 
It requires, however, great care in carrying out, the 
chemicals used and temperature employed requiring to 
be suited to the peculiarities of the gypsum. The de¬ 
sired result is extreme hardness, combined with non-ef¬ 
florescence. Keen’s cement is practically non-efflores- 
eent, as if applied on a dry wall containing no soluble 
salt, in itself there would be no efflorescence that would 
spoil paint. Perhaps one should not say that Keen’s 
cement, or at least all brands of it, are absolutely non- 
efflorescent, as there is generally a powdery coating comes 
on the surface, just enough to whiten a colored hand¬ 
kerchief, something like the coat of puff powder used 
on some female faces. On no account should Keen’s 
cement be used on walls as a preventive of damp, as 
it is useless for this purpose. If used on a damp wall, 
or in places exposed to atmospheric influences, it will 
effloresce more or less, as its base is gypsum, which al¬ 
ways remains soluble. In damp situations the walls 
should be rendered or floated in Portland cement before 
the finishing coat of Keen’s cement is laid. The same 
remarks apply to Parian and Martin’s cements. The 


TERMS AND PROCESSES 


139 


Keen’s cement manufactured by Hunkin’s and Willis, 
St. Louis, Mo., is practically non-efflorescent. 

Cornice Brackets .—Brackets or cores are used to de¬ 
crease the amount of materials and weight, and also to 
form a foundation and support for cornice or other 
mouldings. For large exterior work they are generally 
formed with stone, and for small work bricks, tiles, or 
slates are used, which are built into the walls as the 
work proceeds, and roughly fashioned to an approxima¬ 
tion to the profile of the intended cornice or other mould¬ 
ing. For interior work the brackets are sometimes con¬ 
structed with metal lathing, also with spikes and tar 
bands, termed ‘ ‘ spike and rope brackets, J ’ but the oldest 
and most general way for cornice mouldings are “lath 
brackets.” The “brackets” on which the laths are sub¬ 
sequently nailed are cut out of boards from % inch to 
1 V 2 inches thick, according to the size and form of the 
cornice. The section of the brackets should be about 1 
inch less than the profile of the proposed cornice to allow 
for a thickness of lath and plaster. The thickness of the 
plaster should not exceed 1 inch, or be less than y 2 inch. 
If too thick it is a waste of materials, and the undue 
weight is apt to pull or spring the laths from the brack¬ 
ets, and if too thin the stuff is apt to crack. The profile 
of the bracket need not follow closely that of the cor¬ 
nice, but a general or approximate outline of the most 
salient members followed. Any thin projecting mem¬ 
bers may be subsequently strengthened by means of 
projecting nails and tar-strings similar to a spike and 
rope bracket; also by using extra hair and plaster in the 
roughing out stuff. Brackets for enriched cornices re¬ 
quire special notice. Unless a due allowance is made for 
sinkings for the thickness of the cast enrichments and 
a correct form of bed, there will be unnecessary trouble 


140 


CEMENTS AND CONCRETES 


in cutting and hacking the lath work and brackets when 
the running of the cornice is commenced. There is a 
marked difference between the section of a running 
mould for an enriched cornice and that of a plain cor¬ 
nice, even if the profile of both are the same. To avoid 
mistakes of this nature the plasterer should supply the 
carpenter with a section of the brackets, taken after the 
bed of the enrichments are set out on the tracing of the 
proposed cornice. 

Skeleton brackets is a term applied to a method some¬ 
times used for coring out angles, to save materials where 
there are no brackets, and for small mouldings. This is 
effected by placing the mould in position and then fitting 
a piece of lath in a vertical position, and allowing a space 
of about % inch from the face of tlie latl1 to the nearest 
part or most prominent member of the mould. A mark 
is then made on the ceiling and wall at the top and bot¬ 
tom of the lath. Similar marks are made at the other 
end of the wall and ceiling, and then a line is struck on 
the marks, from end to end of the ceiling and wall, by 
means of a chalk line. The stuff which forms the parts 
of the screeds inside the lines is cut away, dusted, wetted, 
and then a narrow strip of gauged coarse stuff is laid 
along the lines where the ceiling and wall screeds are 
cut, and the laths which have been previously cut to the 
length of the first or trial one are fixed vertically into 
the gauged stuff, keeping them apart as in ordinary lath¬ 
ing. They are further secured by laying strips of 
gauged stuff on the outward surfaces at the top and bot¬ 
tom ends. After the stuff is set, the cornice is run in 
the usual way. 

Cornices. —Cornices, either plain or enriched, are 
formed with a running mould cut to the profile of the 
intended cornice. The formation of cornices consists of 


TERMS AND PROCESSES 


141 


constructing the mould, making the running screeds, 
fixing the running rules, running the cornice and mitring 
the angles, with the addition of fixing the cast ornament 
for enriched cornices. Cornices were formerly run in 
short lengths and in sections. Two, three, and even four 
moulds were employed for cornices that are now 4one 
with one. For large cornices, where the mould is diffi¬ 
cult or sluggish to run, or apt to jump, the bearings 
should be greased or brushed with soap or dusted with 
powdered black lead or French chalk. Running moulds 
are run in some places with the left hand, from left to 
right, and the mould plates are also fixed to the left hand 
side, having the bevelled part of the stock to the right 
or running side. In America the plates are fixed on the 
running or right side, and the mould is run with the 
right hand from right to left. The way of running from 
left to right with the left hand allows more freedom, 
especially in small mouldings, for the right or trowel 
hand to assist in feeding the cornice with the stuff that 
gathers on the mould. It also gives more freedom to 
his partner who is laying on the stuff, as with the hawk 
in his left hand and his trowel in his right he is able to 
work in a natural position, namely, from left to right, as 
in laying coarse or setting stuff on walls, whereas, when 
the mould is run with the right hand, and from right to 
left, the worker has not so much power or freedom in 
assisting to feed the mould with his left hand. His part¬ 
ner, who is laying the gauged stuff, is working back- 
handed, and if using a laying trowel, can only work from 
its heel instead of from the point as is usual; and if 
using the large gauging trowel for laying on every 
trowelful used must be put on with a backhanded turn. 
It may be a matter of opinion as to which method is 
better, and depends a good deal upon which way the man 


142 


CEMENTS AND CONCRETES 


has been taught, but the manner of running the mould 
and laying on of stuff from left to right, the same as 
in writing, is the most natural. Running screeds are 
used as bearings for running moulds. They are com¬ 
posed of gauged stuff,. and made straight with floating 
rules. Screeds for cornices are formed with raw or with 
gauged coarse stuff. They are next traversed. The 
line of the screed is got by placing the running mould 
in its true position or at one end of the wall, and mak¬ 
ing a mark on the floating screeds at the outside of the 
nib and the bottom of the slipper. The same operation 
is repeated at the other end of the wall, and a continuous 
line from one mark to the other made on the ceiling wall 
by means of a chalk line. A narrow strip of gauged 
putty and plaster is now laid on the lines by one man, 
while his partner follows on with a traversing rule, fork¬ 
ing the rule with a slanting motion, and moving back¬ 
wards and forwards until the screed is just and true. 
Where the walls are very long, running screeds are done 
by two men working a long straight edge or floating 
rule. The screed is afterwards further fined by draw¬ 
ing a cross-grained hand float three or four times over 
it in a longitudinal direction. Where the coarse stuff 
screeds are not gauged, the running screeds are made in 
a similar manner, but the putty is mixed with an equal 
proportion of setting stuff before gauging. The addi¬ 
tion of sand gives more resisting power to the wear of 
the nib and slipper of the running mould. The run¬ 
ning screeds are made on the long sides of the room, 
and when set they give a bearing for the end screed in 
its true position at one end of the wall. 

Fixing the running rules is the next operation. This 
is done by placing the running mould in its true position 
at one end of the wall, taking care that the mould is 


Elevation of Corinthian Entablature and Plan of Cornice at Extern vl Angle. 

PLATE 5. 


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# r < M -- .r, •<* 'l '•**««» > 













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TERMS AND PROCESSES 


143 


“square,” that is, that the perpendicular parts of mem¬ 
bers are plumb with the wall. This may be tested with 
a plumb bob hanging over the side of the mould, and by 
seeing that the line of the plumb bob hangs properly over 
a marked line which has been previously made by squar¬ 
ing off from a square member or by extending a parallel 
line from an upright member of the mould. When the 
mould is plumb and square, a mark is made on the ceil¬ 
ing screed at the outside part of the nib, and another 
made on the wall screed at the bottom of the slipper. 
The same operation is repeated at the other end of the 
wall, and the line extended from mark to mark by using 
a chalk line. The line in this case should be blackened 
by means of charcoal or burnt stick, as it shows better 
than a white line on the light-colored screeds. As the 
chalk line may sway when striking the wall line, this 
line should not be trusted for fixing the running rules 
to. This may be proved by placing the mould every 3 
or 4 feet apart in the length of the wall, taking care to 
keep the outer edge of the nib at the ceiling line; then 
marking with a gauging trowel at the bottom of the slip¬ 
per. Nails are now driven into each of these marks and 
left projecting as a guide for fixing the running rules. 
The running rules should not be less than 2% inches 
wide or more than 3 y 2 inches wide and y 2 inch thick, 
being made cut of good redwood or pine planed on both 
sides and edges. The rules are now fixed into the wall 
screed either by nailing them to the studs or into the 
joints of the walls. They are also fixed by wetting one 
face of the rule and laying dabs of gauged putty and 
plaster about two feet 6 inches apart. The rules are 
now pressed on the wall while the stuff is soft, taking 
care not to force the guide nails out of position. The 
rules are further secured by laying patches of gauged 


144 


CEMENTS AND CONCRETES 


stuff underneath the rule partly on the wall and rule 
where the dabs are. When the rules are fixed by nail¬ 
ing, it is apt to crack the first-coat of floating, and the 
joints of the wall are not always easily found. The 
coarse stuff for the first-coat of cornice brackets should 
be extra haired and carefully scratched to give a strong 
foundation for the following coats of gauged stuff, which 
in many instances is extra thick at bold or projecting 
parts of the mouldings. 

For large moulding and wire lathing it is best to leave 
the brackets uncoated when first coating the general 
work until the cornice running is commenced, and then 
to rough out the whole cornice from the lath work with 
gauged coarse stuff. This gives uniform suction and 
strength. If the brackets are lathed with wood, they 
should be first-coated with gauged coarse stuff and 
scratched before the screeds are formed, so as to allow 
time for the lath work to settle before the mouldings 
are roughed out. Weak laths frequently twist by moist¬ 
ure from the first-coating, and gradually settle or re¬ 
sume their original form during the drying of the first- 
coating. Leaving the lathed brackets uncoated also 
forms a vent for the moisture from the wall and ceiling 
first-coating, thus allowing it to dry sooner. The coarse 
stuff for roughing out the cornice should be gauged uni¬ 
formly in strength and consistency, as unequal gauging 
tends to cause unequal swelling in the material, conse¬ 
quently the mould is more difficult to run true. The 
coarse stuff should be laid regular in thickness, taking 
care to gradually build up and form all thick parts and 
projecting members with the trowel to prevent the stuff 
from dropping and the mould from dragging it off, as 
generally happens if the stuff is laid in thick and irregu¬ 
lar coats. When roughing out large mouldings with 


TERMS AND PROCESSES 


145 


coarse stuff, the members of the mitres should also be 
filled in and ruled fair before the running with gauged 
putty is commenced, because when mitrmg, it will be 
more easily and quickly done, materials will be saved, 
and when finished, the whole will be more uniform in 
color. 

When all the mouldings are roughed out, the plaster 
muffle or muffle plate, as the case may be, is taken off, 
and the running with fine gauged putty commenced. 
The gauge board and all tools should now be cleaned to 
free them from grit. A ring of putty is formed on the 
gauge board, leaving the bottom of the board clear; 
water is put in the ring and the plaster quickly and 
evenly sprinkled over the water, taking care not to sprin¬ 
kle it on the putty ring. The plaster and water are 
mixed together by stirring with the point of a trowel. 
The putty is then quickly mixed with the gauged plaster 
by using the trowel and turning it over with the hawk. 
It is put on with a large gauging trowel, or if the mem¬ 
bers are large, with the laying trowel, following the form 
of the mouldings. The mould is then run along by one 
man, who also feeds the moulding with any stuff that 
may gather on the side of the running mould. This 
operation is continued until all the members of the 
mouldings are filled out. A thin gauge of fine putty, 
having less plaster than the previous gauges, is lightly 
drawn over with a trowel, or brushed over the flat num¬ 
bers, and thrown with a brush for small or .dry mem¬ 
bers. This mould is then quickly and steadily run along 
the cornice from beginning to end and finished. If the 
moulding is extra large in girth, or a long length of 
moulding has to be run, extra men are required to lay 
the stuff, while two may be necessary to run the mould. 


146 


CEMENTS AND CONCRETES 


When running small mouldings, say of 10 or 12 inches 
in girth, one man can run and feed the mould while his 
partner is laying on. When all the mouldings are run 
around, the running rules are taken down, the screeds 
cleaned and scraped, and any holes or defects caused 
by nails or patches used for the rules made good by fill¬ 
ing up with gauged putty. If soap, black lead, or any 
other materials already mentioned arc used to aid and 
ease the running of the mould, they should be scraped 
off with a drag as soon as the cornice is run off, other¬ 
wise they will prevent the finishing coats for wall and 
ceiling from adhering to those parts. 

To Set Out and Construct Corinthian Entablature .— 
To enable the plasterer to set out a full size or working 
drawing from the architect’s design, also to comprehend 
the cornice and the architrave, which are sometimes used 
alone or as separate mouldings, their proportions with 
that of the entire entablature are given. The entabla¬ 
ture and the details of the enrichments of the coffers 
and modilliens are shown on plate. 

The whole height of the entablature is divided into 
ten parts, giving three to the architrave, and three to 
the frieze, and four to the cornice, as shown by the first 
upright scale at Fig. 1. This figure shows the combined 
section and elevation of the entablature. The height 
of the architrave is subdivided into five parts to form 
its members, as shown by the second upright scale. 
Projection is taken from the lower fascia, and is equal 
to one-fourth part of its height. As the cornice of the 
Corinthian order is frequently used alone as a separate 
moulding, an enlarged view with figured details is given, 
see illustration Fig. 4. It is necessary that the details 
of the cornice should be mastered before proceeding with 
the entablature. See Plate 1. 


TERMS AND PROCESSES 


147 


With regards to the enrichments of the entablature, 
as shown in Pig. 1, the whole must be set out and so dis¬ 
posed and arranged that the centre of each will be in line 
with each other, or, in other words, that they are regu¬ 
larly disposed perpendicularly above each other, as 
shown from A to B (Fig. 1) where it will be seen that 
the centres of the modillion, dentil, egg, and other bed- 
mould enrichments are all in one perpendicular line. 
Enrichments set out in this way are said, in plasterers ’ 
parlance, to 4 4 principle. ’ ’ Nothing is more careless, con¬ 
fused, and unseemly than to distribute them without 
any order or principle, as they are in many buildings. 
The centre of an egg answers in some places of the cor¬ 
nice to- the edge of a dentil, in some to the centre, and 
in others to the space between, all the rest of the enrich¬ 
ments being distributed in the same slovenly artless 
manner. The larger parts must regulate the smaller. 
All the enrichments in entablatures are governed by the 
modillions, or mutales,- and distribution of these must 
depend on the interval of the columns, and to be so dis¬ 
posed that one of them may come directly over the centre 
of the column, as shown in the present example at C 
(Fig. 2), the axis of each column. 

The enrichments must partake of the character of the 
order they enrich. When the frieze is enriched, and the 
enrichment may be characteristic of the order, or it may 
serve to indicate the use of the building, the rank, quali¬ 
ties, profession, and achievements of the owner. Hav¬ 
ing set out the profile and the enrichments, making the 
running mould and the running mouldings now claims 
attention. For large work the cornice and the archi¬ 
trave are run separately, the cornice being run from the 
slipper screed made on the frieze and a nib screed, and 
the architrave from a slipper screed made on the wall 


148 


CEMENTS AND CONCRETES 


and a nib screed made on the frieze. Sections of the 
cornice and architrave running moulds are shown at 
Fig. 4. 

It may be here remarked that the nib and slipper 
bearings of the cornice and architrave running moulds 
are made for work on ceilings and walls; but if the 
entablature projects or is independent, and supported by 
columns, the nib of the cornice mould must be cut so 
as to bear and run on a nib running rule fixed on the 
weathering of the cornice, and the slipper of the archi¬ 
trave running mould cut so as to bear and run on a 
running rule fixed on the soffit of the architrave. The 
frieze, if plain, is set by hand; and if enriched, a bed 
for the enrichment must be made by running a small 
part of the bed at the top and bottom of the frieze when 
running the cornice and architrave mouldings. In this 
case the screed on the frieze must be set back to allow 
for the plate or ground of the ornament, and the nibs 
and slippers of the running moulds extended at these 
parts. In setting out the mould plates an allowance 
must be made for the bed of the various enrichments, as 
previously described. 

The profiles of the three largest enrichments are indi¬ 
cated by the dotted lines. The angles of the beds of 
these enrichments are splayed, as shown, to save fine 
plaster used for the cast work. This also strengthens 
the top member of the architrave while it is being run. 
It will be seen that an in-dentil is used in this cornice, 
as shown by the dotted line at 1 on the elevation. This 
is the space between the face or main dentils. The in¬ 
dentil is run with the mouldings, and the dentils are cast 
and planted. The in-dentil and the dentil may also be 
cast together in short lengths, and then planted. In 
this case the running mould must be cut to form a bed 


TERMS AND PROCESSES 


149 


for the combined dentils, as indicated by the dotted line 
on the outside of the section of the running mould. The 
dotted line on the section of the running mould shows 
the section of the main dentil. In some examples the 
external angles of the bed of the dentils are filled in with 
an ornament fashioned like a cone or pineapple, instead 
of using an angle dentil. An enlarged view of this class 
of ornament fixed in position is shown at Fig. 11. The 
bed of the small enrichments is made square as shown. 

When setting out the mould plate, the profile of the 
soffit of the corona must be taken through the centre of 
the sunk panel, as shown by the shaded part at Fig. 3, 
thus forming the raised part of the mould as shown at 
Fig. 4. 

The most intricate part in the construction of a Cor¬ 
inthian cornice consists in the formation of the coffers, 
as shown at Fig. 2. This is a plan of the cornice at an 
external angle. F is a coffer, and M is a modillion or 
“block/’ as it is commonly called. The coffer consists 
of a sunk panel, with an enrichment on the four sides, 
and a rose or patera in the centre as shown. A section 
of the coffer is shown at Fig. 3. The coffers are formed 
by fixing a “style,” as from S to S (including the side 
enrichments), on the sunk panel, so as to connect the 
two run plain sides of the soffit and form two sides of 
the coffer. The lines in the front and back of S and 
S indicate the joints of the style before they are stopped. 
It will be understood that the style is fixed before the 
block is fixed. A plan of the complete style is shown at 
Fig. 5. When making the model of the style, the side 
enrichments must be set out mitred and fixed on the 
plain part of the style, and a perforation made in the 
centre to act as a key for the fixing stuff used when 
fixing the block. A mark must also be made in the cen- 


150 


CEMENTS AND CONCRETES 


tre of the front of the style to act as a guide when fixing 
the styles. The model of the style is moulded in wax, 
taking care to splay the back and front edges and the 
centre perforation, also the mitres of the enrichments, 
to allow the mould to draw in one piece. These parts 
are trimmed square after the styles are cast. Having 
fixed two styles, the front and back parts of the coffer 
enrichments, as shown at Figs. 6 and 7, are fixed; then 
the patera (Fig. 8) is fixed; and then the joints of the 
styles are stopped, which completes the coffer. This 
done, the block (Fig. 9) is fixed, and then the small en¬ 
richment (Fig. 10) is fixed, thus completing a part of 
the soffit of the corona. The other parts are of course 
made and fixed in a similar way, but the positions of 
the coffers and blocks must be set out on the whole 
length of the cornice before the fixing is commenced. 

Setting out coffers and blocks is a simple matter, yet 
it requires care to ensure accuracy. First fix a coffer 
and a block in each mitre, as shown at the external 
mitre (Fig. 2) ; then from the centres of these blocks set 
out the whole length of the cornice. This is best done by 
measuring the full length of the cornice from the mitre 
blocks, and dividing the total by the combined width of 
one modillion and a coffer, and if there is no remainder, 
the combined width is marked on the soffit; but if there 
are a few inches over, they are divided among the given 
number of blocks. The marks are proved by going over 
them with a compass or a wood gauge. When the exact 
positions of the centres of each coffer with the block is 
ascertained, the marks are extended across the corona 
and down the plain member on which the back end of 
the block rests on by the aid of a square. These ex¬ 
tended marks or lines give the centres for fixing the 
styles of the coffers and the blocks. Fixing the coffers 


TERMS AND PROCESSES 


151 


and the blocks is the next part of the process. This 
being done, as already described, taking care to use the 
centre mark on the coffer as a guide for fixing it fair with 
the centre lines' on the soffit, and using a wood square to 
prove the square of the style, also using the edge of the 
square to prove the level of the ccffer with the run sides 
of the soffit, then clean off any excess stuff that may 
exude at the keyhole and edges of the style. After this 
the back and front side enrichments are fixed, as already 
mentioned. Before fixing the paterae a keyed or under¬ 
cut hole must be cut in the sunk panels to give a key for 
the stuff that is used for fixing the paterae. A corre¬ 
sponding keyed hole must also be formed on the back 
of the paterae. This is best done by making the desired 
size of sinking in the model of the paterae before it is 
moulded. These sinkings must be undercut after the pa¬ 
terae are cast. 

The model of the paterae is generally moulded with a 
front and back waxed mould. For large paterae, or those 
having a deep projection a piece of twisted galvanized 
or copper wire, sufficiently long to enter the keyed holes 
in the paterae and the soffit, should be inserted in the 
fixing stuff when fixing the paterae. This method should 
always be adopted where the bedding surface of the pa¬ 
terae is small, so as to enable it to resist the weight of a 
brush while being painted or gilded. If the paterae are 
extra deep, and project below the line of the soffit, they 
should be fixed first, otherwise they are liable to get dis¬ 
turbed when fixing the blocks and other enrichments. 

The modillions should be fixed with .stiff gauged stuff 
for the keyed holes in the styles, and the corresponding 
holes in the blocks (which are made while being cast), 
and using softer gauged stuff for the bedding surface of 
the block. After the fixing stuff is laid, place the block 


152 


CEMENTS AND CONCRETES 


in position, and work it gently but quickly from right to 
left, so as to force the excess stuff out, and obtain a true 
and solid bed, taking care that the centre of the block is 
linable with the centre mark on the soffit, and using a 
square to prove the squareness of the block, and then 
clean off the excess stuff. The small enrichments (Figs. 
6, 7, and 10) are fixed with soft gauged stuff, so that 
they can be easily and quickly fixed. Small cast work 
of this kind should always be fixed with soft gauged 
stuff, as there is very little weight to carry until the stuff is 
set. The suction alone between the two bodies is often suf¬ 
ficient to support the cast until the stuff is set. These small 
enrichments are moulded with a face or front wax mould. 


Modillions or blocks were 
formerly cast in three parts, 
namely, the body, the main part 
of the leaf, and the tip or curled 
end of the leaf; the body being 
cast in a wax piece mould (some¬ 
times a plaster piece mould), and 
the leaf and its tip in a front and 
back wax mould, but now the 
complete block is generally cast 
in one piece in a gelatine mould. 
The body of the block may be 
cast in a gelatine mould, but 



Modillion. 
NO. 5. 


where the back section of the leaf is clear or away from 
the block near the scroll end, as shown in the accom¬ 
panying illustration, and seen in fine old buildings, the 
leaf should be cast and fixed separately. An enlarged 
view of the plan and side elevation of a modillion is 
shown in illustration No. 5. The bed moulds and the 
other small enrichments in the entablature are generally 
cast in wax moulds. 













TERMS AND PROCESSES 


153 


When fixing the enrichments in an entablature, take 
special care that they all “principle” with each other 
as already mentioned, thus forming a pleasing and artis¬ 
tic finish, which is characteristic of well-designed mould- 
> ings. 



To Set Out a Corinthian Cornice .—The members 
which are enriched in the cornice, shown in the preced¬ 
ing plate, are drawn as plain members on this cornice so 
as to show the profile and method of setting out more 
clear. 




















































154 


CEMENTS AND CONCRETES 


The combined elevation and profile of the cornice 
shown at Fig. 1, in the accompanying illustration, No. 6, 
is an enlarged view of the cornice of the Corinthian en¬ 
tablature. The first upright scale contains four parts of 
the ten into which the whole entablature is divided, as 
on the preceding plate. The second scale is divided into 
five parts, the third of which goes to the modillion, the 
fourth to the corona, and fifth to the cymatium; the first 
and second together are divided into three parts, the first 
for the reversed cyma at the bottom, the second for the 
dentils, and the third for the ovolo. The smaller mem¬ 
bers are in proportion to the greater, as shown by the 
smaller divisions on the scale. The modillions are 1-6 
of the diameter of the column, and their distances two- 
sixths and a half. Half a diameter is divided on the 
corona at Fig. 2 into six parts, of which the width of the 
modillion is two, and the length of it is four. The cap 
projects 1-3 of those parts, and the distance between the 
modillions is five. By this rule the exact distance from 
centre to centre of the modillions is 7-12 of the diameter. 
The dotted line A C answers to the diminished part of 
the column, from whence the cornice is projected; the 
projection being equal to its height, is divided into fpur 
parts, as shown by the scale at the bottom of the cor¬ 
nice. One-fourth of this scale is divided into six parts, 
as shown at C, five of which gives the width of the modil¬ 
lion. The distance between them is in proportion to it 
as figured at Fig. 2. The fillets, F F, of the modillion 
are % of its width, and so is the bead, B. The position 
and size of the sunk panel are indicated by the dotted 
lines in the corona at Figs. 1 and 2, the size being ob¬ 
tained as shown by the figures in the dotted spaces. The 
width of the dentils, D, is obtained by dividing the semi¬ 
diameter of the column marked on the corona at Fig. 2 


TERMS AND PROCESSES 


155 


into fourteen parts, two of which gives the width of the 
dentil, and one the space between them. This space of 
course is also the width of the in-dentil, the height of 
which is one-fourth of the height of the main dentil, as 
indicated by the small division on the inner side of the 
second upright scale. 

The centres and radius for describing the profiles of 
the cymatium or cymarecta, the ovolo, and the inverted 
cyma or ogee members are indicated by small crosses and 
dotted lines. 

Mitring .—Mitring is looked upon by the generality of 
plasterers as a test of speed and ability. As they gener¬ 
ally work in pairs on other portions of the work, their in¬ 
dividual ability is not easily seen, but when mitring a 
man carries the operation through alone. Mitring being 
done by hand, is a near approach to modelling, and is an 
operation of which a dexterous and good plasterer is nat¬ 
urally proud. The quality and time required for mitres 
greatly depend upon the degree of hardness of the run 
cornice, also upon the suction. A mitre can be more 
freely worked and more expeditiously done on a hard 
cornice surface, and where there is a suction. The extra 
absorbing powers of brick walls as compared to lath par¬ 
titions cause the gauged stuff to get firm sooner, and 
enables the mouldings to be more readily blocked out be¬ 
fore the stuff is set. A common error when mitring is 
gauging the stuff stronger than that which has been used 
for the running of the cornice, causing extra swelling 
and difficulty of ruling the members over, and cutting 
the run part of the cornice with the joint rule, especially 
if the stuff sets before the plasterer has had time to rule 
all the members over, and then being stronger, and con¬ 
sequently setting quicker, he has not so much time for 
forming the members. Ordinary sized mitres can be 


156 


CEMENTS AND CONCRETES 


done with one gauge by using less plaster than in the 
gauge for running the cornice, and stiffening the greater 
portion with dry plaster, and using this for roughing out 
the mitre; then using the soft portion left for brushing 
over the members and filling up all holes, and afterwards 
working the joint rule over the metal to take the su¬ 
perfluous stuff off. Should the mitre not be fine enough, 
the gauged stuff can be further softened on the hawk by 
adding water, and working it with the gauging trowel, 
brushing the soft or creamy stuff all oyer the mitre 
again, then working the joint rule again. Small mem¬ 
bers, and those at the top and bottom of the cornice, 
where there is most absorption, should be worked by the 
joint rule first, leaving the large members, drips or coves, 
or where there is a large body of stuff, to be ruled over 
last. The joint rule should always be worked horizon¬ 
tally, especially when dealing with beads and earvettos. 
Drips and large members should be worked with the 
joint rule with an upright motion, because if worked 
down, the stuff may be pulled down. Mitres should not 
be worked, fined, or tooled with small tools, as they can 
and should be brought to a good and straight surface 
by the proper use of the joint rule. Small tools should 
only be used for laying the stuff when required, and 
cleaning out the i itersections of the mitres, quirks, and 
for stopping. A square-ended small tool may be used 
for smoothing flat, straight surfaces. Returned mitres 
and short breaks are “run down,” then cut to the re¬ 
quired lengths and planted. They may also be mitred 
by hand. 

Mitre-Mould .—Various attempts have been made to 
construct a running mould that would form the mitres 
simultaneously with the cornice running. Most plasterers 
will have heard of, and some may have tried to make 


TERMS AND PROCESSES 


157 


and work a mitre-mould to save hand labor. Those who 
have tried it will have found the results far from satis¬ 
factory. The subjoined illustration No. 7, shows the 
method of setting out and constructing a mould intended 



for forming the moulding and mitres in one operation. 
The mould is made by fixing the metal plate at an angle 
of 45 degrees on the slipper, or in other words fixing the 
iron plate at one angle of a square slipper, which allows 
the mould to run nearly up to the angle, one face of the 
slipper being used for one side of the wall, and the other 























































158 


CEMENTS AND CONCRETES 


face at right angles being used for the other side of the 
wall. Fig. 1 shows the method of setting out the profile 
of mould. A is a given section of a moulding, and B 
is the section of the moulding at the mitre. To obtain 
this, first draw the moulding A full size, and then extend 
the ceiling line and draw another wall line. Then from 
the projection of the top member draw an angle line at 
45 degrees. Carry up the projections of the various 
members to the angle (or mitre line) and then draw hori¬ 
zontal lines from the various members; also centre lines 
of large members as from a to 1 (the vertical letters). 
Take off the lines a to 1 (diagonal letters) on the angle 
line, and set them on the ruling line from a to 1 (hori¬ 
zontal letters), and then laying them down to the hori¬ 
zontal lines, the intersections give the profile for the 
mitre-mould. Fig. 2 shows a side elevation of the mitre- 
mould, and Fig. 3 shows a front elevation. It will be 
seen that the mitre-mould is an expensive and unsatis¬ 
factory fad. The time expended in setting out the elon¬ 
gated members, making an extra mould, and cleaning 
out the intersection by hand (as the mould does not leave 
a finished mitre), also making good the parts broken by 
drawing out the mould from interlocked or undercut 
members in the moulding, is not repaid. An average 
plasterer would put in all the mitres of an ordinary 
sized room while the mould was being made. The mould 
will only run into every second angle, and must be taken 
off and reversed to fit the next. It may seem a waste of 
time and space to describe and then show the utter use¬ 
lessness of a mitre-mould, but having met many plas¬ 
terers who stated that they had used or had seen a mitre- 
mould that worked wonders, I am constrained to give a 
description, not only to save future futile controversy, 
but to show that in this book the much-debated trade 


TERMS AND PROCESSES 


159 


subject has not been omitted. In concluding this sub¬ 
ject, it may be stated that not any one of the mitre-mould 
plasterers would or could practically explain the modus 
operandi of this mysterious mould. 

Fixing Enrichments .—Enrichments should be fixed 
straight, square, plumb, and firm. Cornice enrichments, 
such as bed moulds, friezes, &c., for which a bed or sink¬ 
ing to receive them is formed by the running mould, do 
not require such strong gauges stuff as soffits, medallions, 
or other hanging casts. For light enrichments the gauged 
putty and plaster should never be stronger than that 
used for the cornice, and clean strong size water should 
be used. This gives more time for fixing a number of 
casts, and improves the cementing force. The bed for 
the cast work should be scratched, dusted, and wetted 
before the cast work is applied. A small portion of fine 
plaster (the same as used for casting the enrichments) 
should be gauged with clean size water, to be used for 
the joints. The gauged fixing stuff should be spread 
evenly over the back of the cast and over the scratched 
bed of the moulding. No more should be laid on than 
will fully fill up the scratches. Then place a small piece 
of the white or joint gauge on the point, and press the 
cast into position by gently but quickly sliding the cast 
twice or thrice backwards and forwards to expel the air 
and incorporate the two bodies. It is a mistake to dab 
a lump of gauged stuff at random on the back of the cast 
and press it on the bed, as the stuff does not properly 
enter the scratched part of the bed, and the contained 
air prevents proper cohesion and solidity. When too 
thick a coat of stuff is laid on the coat, straight and even 
fixing is more difficult. The excess stuff oozes out at the 
sides, and unless time and care be taken in cleaning it 
off, the moulding, or cast, or both, get damaged. A 


160 


CEMENTS AND CONCRETES 


small portion may also ooze out in the first method, but 
it will be so thin that it can be brushed off while soft. 
When fixing medallion blocks or trusses, a dovetailed 
hole should be cut in the vertical and horizontal parts of 
the bed, and similar holes in the blocks (which are made 
when being cast) are filled in with gauged stuff and 
applied in position. If the cast should be very heavy, 
or of Portland cement, it is further secured by inserting 
a slate or iron dowel while the stuff is soft, allowing a 
portion of the dowel to project to enter into the body of 
the cast. Heavy casts should be temporarily supported 
by wood props until the fixing stuff is set. When fix¬ 
ing heavy casts the plain surface of the plaster work 
should be cut as far as the lath to obtain a better and 
stronger key. The putty in the fixing stuff should be 
mixed with long strong hair or tow, as described for rib 
mouldings or ceilings. Hair or tow may also be used 
advantageously in fixing Portland or other cement work. 
Cast work, when extremely heavy, should be further se¬ 
cured by means of long screws or bolts, placed so as to 
pass through the cast work and into the timber, the 
casts being bedded with gauged haired stuff and tem¬ 
porarily propped up. The screws or bolts should be 
fixed before the stuff is set to a^void the probable dis¬ 
turbance of the gauged bedding. Before fixing any cast 
work they should be placed in position to prove their 
correct fitting. Centre, side and end lines should be 
made on the surface of the bed to give a guide for fix¬ 
ing. It may be necessary to fix nails at intervals in the 
lines to give a further guide. 

Mitring Enrichments .—Before fixing continuous or 
space cast work, the length and width of the panel or 
room should be set out to prove that the mitres are equal- 
sided, balanced and have flowing lines. Nothing look# 


TERMS AND PROCESSES 161 

so slovenly or unworkmanlike as a mitre in an ornament 
cut haphazard, with the leading stem disjointed or 
springing out of a flower or tendril. If the design is 
vertical, say a bed mould or frieze with an alternate leaf 
and husk, what can be more offensive to artistic taste 
than a part of the leaf on one side and a part of the 
husk on the other side of the mitre! There is no ex¬ 
cuse for this want of taste and wanton treatment. A 
little time expended in setting out the work will obviate 
these defects. Where there are no shrinking and stretch¬ 
ing casts the mitres can be eased by stretching or shrink¬ 
ing the cast work at the joints. Stretching or shrinking 
are evils, and it depends on the design of the enrich¬ 
ments which of the two is the lesser, but in most instances 
shrinking is the greater evil. Shrinking does not require 
so much labor to make the joints good. Stretching does 
not show quite so much, especially if the joint is well 
modelled and of the same color. It also gives greater 
scope and freedom. It has already been mentioned that 
in good shops the breaks or other short lengths are set 
out in the shop and that there are stretching and shrink¬ 
ing casts and mitres modelled and made to facilitate the 
formation of good mitres. This latter method is cer¬ 
tainly the cheapest and most satisfactory in the end. The 
setting out is best done by cutting a lath as a gauge to 
the length of the cast and marking the length of each 
cast temporarily on the bed of the cast work from mitre 
to mitre. When the mitre has been determined on and 
the casts set out to come in, the marks are made more 
distant to give a guide for fixing each separate cast as 
required. It is better to measure thrice than alter twice. 
Space ornaments should also be set out accurately, but 
there is no difficulty in the mitres, as the intervening 


162 


CEMENTS AND CONCRETES 


space between each cast can be increased or diminished 
as required. 

When fixing medallion blocks, dentils or paterae, the 
mitres should be fixed first and then the spaces and posi¬ 
tions set out. Special care must be taken when mitring 
enrichments with distinctive vertical parts, such as fig¬ 
ures, or pendants of flowers, or fruit in friezes, that the 
cast work is not unequally or irregularly scratched so as 
to enable them to come to an equally balanced mitre at 
the angles. Where there are no stretchers the cast work 
should be cut between the main vertical parts, so that the 
joint on each side will be equal, or, in other words, that 
the vertical parts will be equidistant from the main or 
other parts when fixed. The same remarks apply to 
shrinking. The mitres of running enrichments, such as 
soffits, etc., are made up with bands or ribbons, which 
are cast or worked in situ by hand. The latter way is 
the quickest and most artistic. Another plan is *to fix 
paterae or drops at the internal and external mitres. 
The scroll work of the enrichment is then formed to 
spring from the paterae and finish at the patera at the 
next mitre. Sometimes the inner member at each side 
of the soffit is worked across at right angles at each mitre, 
thus forming a small square sinking or panel, which is 
then filled in with a patera or drop. 

Bed moulds, such as an egg and dart, have internal and 
external mitre leaf modelled and cast. This is a neat 
and quick way of forming mitres. A good cornice, with 
well-modelled and effective ornament, may be disfigured 
and spoiled by careless mitring, yet it is as easy (and in 
many cases more so) to make good and satisfactory 
work. It is therefore best to set out correctly and make 
sure of a correct finish before beginning to fix. Illustra- 


TERMS AND PROCESSES 163 

tion No. 8 shows the method of mitring various forms 
of fret enrichments. 

Pugging .—Pugging or deafening is a body of plastic 
materials laid on boards fixed between the joists of a 
floor, or lath and plaster partitions. It is intended to 
prevent sound and smells from passing from one room 
to another. Pugging is generally performed by laying 
a thick coat of coarse stuff on a foundation of rough 
boards on fillets, which are nailed on the sides of the 
joists. Chopped hay, straw or ferns, mixed with lime, is 









'cFret Ornaments, showing their Mitres. 

NO. 8. 

sometimes used for the plastic coat. Coarse plaster with 
and without reeds is also used in some districts. Saw¬ 
dust is sometimes substituted for reeds. Pugging may 
be done by forming a foundation with thick rough lath 
wood. On this a coat, about % inch thick, of coarse stuff 
is laid, and when dry a layer about 2 inches thick of dry 
ashes or lime riddlings is deposited on it. The upper sur¬ 
face is then sprinkled with water and finished with a coat 
of coarse stuff. This makes sound-proof work, but in the 





















































































































164 


CEMENTS AND CONCRETES 


event of subsequent damage or alterations the dry ashes 
run out, causing further dust and damage. In some in¬ 
stances the dry ashes are gauged with lime. When laid 
the upper surface is beaten and smoothed with a shovel. 
This makes sound-proof and durable work, impervious to 
vermin. Partitions are deafened by lathing between 
the studding and then laying on a coat of coarse stuff. 
When dry the partition is lathed and plastered in the 
usual way. Pugging slabs of fibrous plaster are now 
largely employed. They have the advantage of being 
light and dry and are rapidly fixed. 

Sound Ceilings .—No lath and plaster ceilings can be 
made sound and free from cracks unless the joists are 
well seasoned, firmly fixed and sufficiently strong to 
carry the overhead weight, as well as sustain the weight 
of the lath and plaster, and resist jarring. Ceiling joists 
should never be more than 12 inches apart from center 
to center. Where double lath is used the joists may be 
14 inches from center to center. Good laths, with break 
joints every three feet, and well nailed, are also impera¬ 
tive. If the above dimensions are exceeded the laths 
are liable to give or twist on account of the weakness of 
the laths or the weight of the plaster, or both com¬ 
bined. If the joists exceed 2 inches in the width they 
should be counter-lathed or strapped to ensure a key for 
the plaster. Where it is impracticable or inconvenient 
to fix the ceiling joists so close they should be brand- 
ered. This strengthens and stiffens the joists, also gives 
a free key for the plaster and forms a sound, level ceil¬ 
ing. 

Brandered or strapped ceilings are done by nailing 
wood straps or fillets across the under sides of the joists. 
The fillets are from iy 2 to 2 inches square and are fixed 
from 12 to 14 inches from centre to centre. The sizes 


TERMS AND PROCESSES 


165 


and distance apart varies according to the thickness of 
the lath and the class of plaster work. Brandered ceil¬ 
ings are largely used in some places and make good 
sound ceilings. 

Cracked Plaster Work .—Cracks in plaster work are 
due to various causes. They may act individually or in 
combination. Cracks are often caused by settlement in 
the building. These cracks may be easily discerned by 
their breadth, depth and length. They also arise from 
the shrinkage of bad or unseasoned timber used in the 
construction or framing of the building, which may 
cause displacement in the joists or the laths. Cracks 
are sometimes caused by the laths being too weak, or by 
too much plaster being laid on weak laths, or too little 
plaster laid on strong laths. Other causes are the too 
sudden drying of the work, strong winds or heat, Jie 
laying of one coat of mortar on another coat, or on walls 
that have a strong suction which absorbs the moisture or 
f 4 life ’ ’ of the coat being laid, when it becomes short, or 
crumbly, scaly and apt to peel or fall off. In this last 
case it does not set, but only dries and shrinks, which 
gives rise to cracks, and eventually falls or crumbles 
away. The use of bad materials, insufficient use of lime 
and hair, or scamping of labor is often followed by 
cracks. Insufficient labor and unskilled workmanship in 
the application of the materials is a great source of 
trouble, but it will be understood that the best quality 
of labor will not make bad materials good and strong; 
and, on the other hand, the best materials will not com¬ 
pensate for bad labor. It is only by judicious selection 
of materials and their skillful manipulation that a high 
and enduring class of work can be obtained. 

Repairing Old Plaster .—Repairing is also termed 
“patching,” “jobbing” and “making good.” When 


166 


CEMENTS AND CONCRETES 


repairing or making additions to old plaster work, care 
should be observed in cutting the joints so that the key of 
the existing work is not injured or broken. The joints 
one way should be cut on the studding or joists and in 
a line with the laths the other way. A joint at the edge 
of a lath is stronger than at the center. If the lath work 
is weak the joints should be cut diagonally. Never use 
a hammer to cut joints on lath work, for the repeated im¬ 
pacts will weaken and crack the old work. If the old 
plaster is hard, cut the joint with the saw or with a ham¬ 
mer and chisel and finish with a strong knife. Avoid 
acute angles in patches. Square, round cr oval patches 
not only look better but are much stronger than zigzag 
ones. Having cut the joints neat and square on edge 
and then repaired the old lath work, brush the joints 
and the laths with a dry broom and then wet the joints, 
but only dampen the lath work, as excessive water tends 
to warp the laths. The joints are sometimes painted to 
prevent damp from extending to the old work or caus¬ 
ing injury to any surface decoration. Gauged coarse 
stuff is generally used for roughing out and gauged putty 
for finishing ordinary work. The coarse stuff is gen¬ 
erally gauged with coarse plaster. For small patches 
the whole thickness is generally brought out in one coat, 
but for large patches it is best to lay a first coat and 
then scratch it in the usual way. If time permits this 
should stand for one day, or even two, to allow the lath 
work to settle. The stronger and stiffer the gauge, the 
less power the laths will have to warp. The floating coat 
is gauged moderately stiff with coarse plaster or with 
fine plaster and coarse in equal proportions. 

When laid, the surface is ruled in with a straight¬ 
edge, keeping it within the line of the old work to allow 
for plaster swelling and a thickness of 1-16 inch for the 


TERMS AND PROCESSES 


167 


finishing coat. It is often necessary to drag the surface 
down to allow the finishing coat to be ruled fair and 
flush with the old work. The surface should be left fair 
but rough. Gauged work should never be scoured, as it 
only kills the plaster, and therefore weakens the body of 
the material. The putty for the final coat should be 
gauged with fine plaster and a little size water. After 
being laid the surface is ruled flush with the old work, 
and when firm it should be smartly trowelled off and 
finally finished with a semi-wet brush. The joints should 
be trowelled flush and smooth and the old part brushed 
to free it from any gauged stuff. All rubbish should be 
damped as it falls, and removed as soon as possible to 
prevent further dust and dirt. 

Parian or other white cements are used for best work, 
or where time is a consideration. All white cements 
having plaster for their basis are manufactured to be 
non-efflorescent, non-porous, durable, free from liability 
to unequal shrinkage (which causes cracks), and free in 
working. They form admirable materials for repairs or 
additions. When making good old or broken lime plaster 
work with any of these cements, the joints and lath nails 
must be painted with red lead, quick drying paint, or 
with shellac. Galvanized nails ought to be used for the 
lath work where these cements are to be used. Small holes 
and cracks are usually stopped with fine plaster gauged 
with putty, or better still, putty water. Parian cement is 
also used for a similar purpose. The holes and cracks 
should be brushed with Parian solution before the stiff 
Parian is applied. This solution is simply fine Parian 
gauged to a thin creamy consistency with water. New or 
damp lime-plastered walls can be painted or papered 
much sooner, and with greater safety, if brushed with a 
thin Parian solution. It is also useful for stopping the 


168 


CEMENTS AND CONCRETES 


suction on dry floating and fibrous slabs before laying 
the final coat. Several of the new patent plaster and 
white cements are well adapted for repairs, or where 
time is limited. 

Gauged Work .—All gauged work should be regulated 
in strength according to the purpose required. A brick 
or stone wall would not require so much plaster as a lath 
partition. Work not subject to friction or wear does not 
require so much plaster. If the work is required for 
immediate use, as with running screeds, or blocking out 
large mouldings, or fixing large castings much plaster 
must be used. The amount of plaster required for scaf¬ 
fold work varies from % to equal proportions for gaug¬ 
ing coarse stuff or setting stuff, and from 1-3 to equal 
proportions for coarse stuff for heavy cornices, and 1-3 
to equal proportions for putty and fixing ornament. The 
amount of plaster also depends upon the quality of the 
plaster, some of which are much stronger than others. 
Coarse plaster that is of a dark and sandy nature is gen¬ 
erally weak, sets quickly, and becomes soft and useless. 
Fine plaster should be used for gauging putty when run¬ 
ning cornices, also for fixing enrichments. All gauged 
work should be gauged with uniformity, each separate 
gauge having the same amount of water and plaster as 
required for the bulk of stuff being gauged. Unequal 
gauging causes hard and soft places in the work, and 
when more plaster is used in one gauge than another 
there is an extra expansion caused by the swelling of 
the plaster, which makes the work more difficult to do 
when floating, setting, running mouldings, or mitring. 

A quart and a pint measure should always be kept on 
the scaffold for measuring the water used for the vari¬ 
ous gauges. The quantity of water will regulate the 
quantity of plaster for each gauge. A proper plaster 


TERMS AND PROCESSES 


169 


box should also be on the scaffold, made to hold a sack of 
plaster, and having a lid made in two halves hinged from 
the centre. This prevents the plaster from getting dirty 
by falling stuff, and from getting damp by absorption 
from the atmosphere. Where there is a large quantity 
or continuous gauging, the box should be placed on a 
stand (this is called a stand-box) to prevent unnecessary 
exertion and loss of time by stooping for each handful. 

When gauging coarse stuff for large surfaces which 
require several gauges to complete the work in hand, size 
water should be used in proper proportions with the neat 
water used for gauging, so as to allow sufficient time to 
properly manipulate the material. In the event of 
gauged stuff setting before the work is laid and ruled off, 
it is difficult to make the surface strong and fair. This 
also allows the various gauges to be laid on or against 
the previous ones while they are in a soft state, thus 
forming stronger joints and better cohesion between the 
various gauges. The use of size water in gauged set¬ 
ting stuff and putty enables the work to be freely trow¬ 
elled and finished. Gauged stuff should not be hand- 
floated, as excessive working destroys the setting powers 
of the plaster. 

Joist Lines on Ceilings .—Common flat ceilings show 
in time the precise position of the joists above, and in 
many instances the position and form of the lath work 
can be easily discerned. Many theories have been ad¬ 
vanced as to the cause of these unsightly lines or marks, 
which are so distressing to the mind and eye. In my 
opinion they are due in a great measure to insufficient 
material and inferior work. The plaster which is be¬ 
tween or separate from the joists is more pervious to the 
atmosphere than that which is in more direct contact. 
The air in passing through leaves behind it particles of 


170 


CEMENTS AND CONCRETES 


dirt assigned in larger measure to the unattached than 
to the attached portions. Dust that finds ingress be¬ 
tween the joints of flooring boards lies on the unattached 
portions, consequently the joists show themselves as 
lighter lines on a more or less dirty background. The 
same causes apply to the lines on the lath work. An¬ 
other cause is that the plaster work is too thin. In many 
instances the floating is brought up from the lath in one 
coat. This is a most pernicious habit, as it is not only, 
the cause of lath lines, but the ceiling invariably cracks, 
and develops spontaneously original patterns indicative 
of rivers, which too often lead like Niagara to a catas¬ 
trophe in the form of falling plaster. Joists and lath 
lines on thin ceilings may be partly obviated by laying 
strong brown paper over the upper side of the lath and 
plaster and then pasting the edges to the sides of the 
joists, so as to form a cover to the plaster work. The 
better and most sanitary way is to lay the work in three 
coats, allow the first coat to dry, consolidate the floating 
coat by well scouring with a hand float, and render the 
setting coat hard, non-absorbent, and impervious to the 
air by thorough scouring, trowelling, and brushing. 

Rough Casting. 

Several years ago I was requested by the Editor of 
“Architecture and Building” of New York to prepare a 
short treatise on the subject of “Rough Casting” for 
publication in that magazine. The article was pub¬ 
lished in almost every architectural journal in the coun¬ 
try, and Mr. Kidder embodied it in his excellent work, 
“Building Construction and Superintendence, Vol. I.” 
I reproduce it here, as the directions given therein have 
been found to be of the very best, and most workmen in 


TERMS AND PROCESSES 


171 


this line of the trade adopt the methods of manipulation 
herein described. 

‘‘Rough casting, or, as it is sometimes called, slap 
dashing, both of which are synonymous with the French 
Jwurdage, rough work, and ravalement, having a similar 
meaning, is a method of plastering the outside of a build¬ 
ing much used in the northern part of Canada because 
of its being durable, cheap and well adapted to keep out 
cold winds during the long winters in that section of 
the world. The methods of applying rough cast and the 
mixing thereof do not materially differ from the meth¬ 
ods adopted in Northern Europe or even in the North¬ 
western States, but it is these minor differences, says a 
writer in an exchange, that make the Canadian rough 
casting superior, so far as durability is concerned, to 
much that is done in other parts of the world. 

There are frame cottages near the City of Toronto and 
along the northern shores of Lake Ontario that were 
plastered and roughcasted exteriorly over 40 years ago, 
and the mortar today is as good and sound as when 
first put on, and it looks as though it was good for many 
years yet if the timbers of the building it preserves re¬ 
main good. Rough cast buildings are plentiful in every 
province in the Dominion from Halifax to Vancouver 
and from Lake Erie to Hudson Bay, and when well built 
and the rough cast properly mixed and properly applied 
the result is always satisfactory. It is quite a common 
occurrence in Manitoba and the Northwest Territories 
in the winter to find the mercury frozen, yet this inten¬ 
sity of frost does not seem to affect the rough casting in 
the least, though it will chip bricks, contract and expand 
timber, and render stone as brittle as glass in many 
cases, and the effect on iron and steel is such as may 


172 CEMENTS AND CONCRETES 

prove dangerous if exposed to sudden and unexpected 
strain. 

In preparing a frame or log building for rough cast¬ 
ing care must be taken in putting down the founda¬ 
tion. A good stone or brick foundation is, of course, the 
best, but where rough casting is intended stone or brick 
foundations are seldom used because of their cost, and 
the builder is compelled to use posts of wood. The 
posts are generally made of white cedar, which has a 
lasting quality of 35 or 40 years if sound when used. 
The posts are put in the ground from 3 to 5 feet, the 
deeper the better, as they should be deep enough in any 
case to prevent frost from forcing them upward. When 
a sufficient number of posts have been properly placed 
a line is struck on them a proper height from the ground 
and the tops levelled off. The sills are then placed—all 
joints being broken on top of posts—and the whole made 
level. These sills and all the other timber, scantlings 
and lumber should be well seasoned, if possible, for the 
greatest enemy to the plasterer is unseasoned timber; 
shrinkage of joists, posts and scantling not only breaks 
the bond of the mortar, but causes great cracks in cor¬ 
ners and angles that no amount of pointing or patching 
can ever make good. 

When the frame is up and the rafter on and well se¬ 
cured the whole of the outside should be covered with 
good, sound, common inch stock pine, hemlock, spruce, 
or other suitable lumber, dressed to a thickness. If put 
on diagonally so much the better, but this is not abso¬ 
lutely necessary if the rough casting is to be of the best 
quality, as will appear hereafter. 

When it can be done it is best to get all partitions set 
in place and lathed, the roof on and all necessary out¬ 
side finish or grounds put in place and made ready to 


TERMS AND PROCESSES 


173 


receive the lath. The carpenter must prepare his finish 
or grounds for finish to accommodate the extra lath, as 
the walls will be thickened accordingly. 

For the cheaper sort of rough casting in one or two 
coats the following method of lathing is employed: Nail 
laths on the boarding—over paper or felt, if paper or 
felt is used—perpendicularly 16 inches from centre to 
centre if 4 foot laths are used, or 18 inches or 1 foot 
from center to center if 3 foot laths are used. The whole 
surface to be rough cast will require lathing this way. 
When done lath as is ordinarily done with No. 1 pine 
lath, breaking joints every 15 inches. Put 5 nails in 
each lath, driving each nail home solid, coat over with 
mortar, well haired, and that has been made four or more 
days; smooth and straighten as well as possible with a 
darby. When done and while yet soft the rough cast is 
thrown on it with such force as to drive the pebbles or 
small stones deep into it. The mixture or dash, as it is 
called, is composed of fine gravel, clean washed from all 
earthy particles and mixed with pure lime and water 
till the whole is of a semi-fluid consistency. This is 
mixed in a shallow tub or pail and is thrown upon the 
plastered wall with a wooden float about 5 or 6 inches 
long and as many wide, made of y 2 inch pine, and fitted 
with a wooden handle. While with this tool the plaster¬ 
er throws on the rough cast with his right hand, he holds 
in his left a common white-wash brush, which he dips 
into the rough cast and then brushes over the mortar 
and rough cast, which gives them, when finished, a reg¬ 
ular, uniform color and appearance. 

For this sort of work the following proportions will 
answer: To one barrel of prepared gravel use a quarter 
of a barrel of putty; mix well before using. This may 
be colored to suit the taste by using the proper materials, 


174 


CEMENTS AND CONCRETES 


as given further on. It must be understood that the fore¬ 
going is the cheapest sort of rough casting, and is not 
recommended where more durable but more expensive 
work is required. 

The best mode of doing this work as practised in the 
Lake district of Ontario is nearly as follows. Have the 
frame of building prepared as indicated in the foregoing, 
with partitions all put in and well braced throughout and 
well secured. Lath diagonally with No. 1 pine lath, 
keeping 1 y 2 inches space between the lath. Nail each 
lath with 5 nails, and break joints every eighteen inches. 
Over this lath again diagonally in the opposite direction, 
keeping the same space between the lath and breaking 
joints as before. Careful and solid nailing is required 
for this layer of lathing, as the permanency of the work 
depends to some extent on this portion of it being honest¬ 
ly done. The mortar used for the first coat should have 
a goodly supply of cow’s hair mixed in with it, and 
should he made at least four days before using. The 
operator must see to it that the mortar be well pressed 
into the key or interstices of the lathing to make it 
hold good. The face of the work must be well scratched 
to form a key for the second coat, which must not be put 
on before the first or scratch coat is dry. The mortar for 
the second coat is made in the same way as that re¬ 
quired for the first coat, and is applied in a similar man¬ 
ner, with the exception that the scratch coat must be 
well damped before the second coat is put on in order 
to keep the second coat moist and soft until the dash or 
rough cast is thrown in. The rough casting is done ex¬ 
actly in the same manner as described for the cheaper 
sort of rough cast work. 

A building finished in this manner, if the work is well 
done, possesses many advantages over the ordinary 


TERMS AND PROCESSES 


175 


wood covered structure. It is much warmer being al¬ 
most air tight so far as the walls are concerned. It is 
safer, as fire will not eat its way through work of that 
kind for a long time. It is cleaner, as it will not prove 
such a harbor for insects. It may be made as handsome 
as desired, for before the rough cast is dashed it may be 
laid off in panels of any shape by having strips of bat¬ 
tens tacked over the soft mortar, which may be removed 
after the rough casting is done and the coloring finished. 
It is much superior to the so-called brick veneered house, 
as it is warmer, more exempt from fire and cheaper. 

For 100 yards of rough casting in the manner 
described the following quantities will be required: 1800 
laths, 12 bushels of lime, iy 2 barrels of best cow hair, 
1% yards of sand, % yard of prepared gravel and 16 
pounds of hot cut lath nails, 1*4 inches long. The gravel 
should be sifted through a y 2 inch mesh screen, and 
should be washed before mixing with the lime putty. 

To color 100 yards in any of the tints named herewith 
use the following quantities of ingredients: For a blue 
black mix 5 pounds of lamp black in the dash. For a 
buff use 5 pounds of green copperas, to which add 1 
pound of fresh cow manure; strain all and mix well with 
the dash. A fine terra cotta is made by using 15 pounds 
of metallic oxide mixed with 5 pounds of green copperas. 
A dark green color is made by using 5 pounds of green 
copperas and 4 pounds of lamp black. Many tints of 
these colors may be obtained by varying the quantities 
given. The colors obtained by these methods are perma¬ 
nent; they do not fade or change with time or atmos¬ 
pheric variations. Many other colors are used but few 
stand like the ones named. A brick color may be obtained 
by the use of Venetian red and umber mixed in whisky 
first and then poured into the dash until the proper tint 


176 


CEMENTS AND CONCRETES 


is obtained. In time, however, like all earthy pig¬ 
ments, these colors fade and have a sickly appearance; 
they answer better in cements than when incorporated 
with fat limes. 


VARIOUS METHODS OF RUNNING CORNICES, 
CIRCLES, ELLIPSES AND OTHER ORNAMEN¬ 
TAL STUCCO WORK. 

Diminished Cclumns .—The diminishing of columns is 
an interesting but somewhat difficult operation. Great 
care must be exercised not to overdo the entasis or swell¬ 
ing. The swell may commence very gradually from the 
base to the capital, or the third part of the column may 
be of the same diameter, and then swell and diminish for 
the remainder of its height. Two methods are here given 
to show how this may be done. These are given more 
to illustrate the method of setting out the diminished 
floating rulest—so necessary to the plasterer—than to 
define the swell or diminishing of a column, which, being 
within limits a matter of taste, pertains more correctly 
to the architect. 

The best instrument for forming a diminished column 
(plain or fluted) is a diminished floating rule, with a 
cutting edge made to the contour of the proposed col¬ 
umn. This rule is used to determine the central posi¬ 
tion of the astragal and base mouldings (which act as 
bearings when ruling off the floating stuff and the final 
coat), so as to obtain a true and uniform diminish, and 
also to form a fair surface. The appended illustration 
No. 9 elucidates the method of setting out diminished 
columns which is also used for setting out the diminished 
rule for both columns. The method for setting out a 
diminished rule for a column that diminishes two thirds 
of its height is as follows: The dimensions of the column 
177 


Fi4 I a 


178 


CEMENTS AND CONCRETES 




Diminishing Columns.—Column Trammel and Diminished„Floaiing_Eui.l 




























































































































METHODS OP WORK 


179 


having been fixed, i. e., the height of the shaft and its 
upper and lower diameters, draw a perpendicular line 
which may be taken as the centre line of the column; 
then set out the upper and lower diameters, as shown in 
Fig. la. This figure also shows one-half of the con- 
structural brick work, and the plaster, which is dis¬ 
tinguished by being dark shaded with the floating rule 
in position. A floating rule for forming the curved and 
diminished surface requires an iron plate, similar to a 
mould plate, as shown, so that it will cut the stuff off 
cleaner and truer, and last longer. The other half of the 
elevation shows the lines and divisions for obtaining and 
setting out the entasis. 

To diminish the column, first divide the height into 
three equal parts then at the lower third (5) draw a 
semicircle equal to the lower diameter of the column. 
Next divide the upper portion of the column into four 
equal parts, as shown at 1, 2, 3 and 4, then draw a line, 
parallel with the axis or centre line of the column, from 
figure 1 at the top of the column, cutting the semicircle 
at 1, divide the remainder of the semicircle into four 
equal parts, which gives the diminishing points. From 
these points draw lines parallel to the axis of the column, 
and from the corresponding figures, or from 2 to 2, and 
so on. In these intersecting points fix pins or nails, and 
bend a flexible strip of wood or metal round the nails, 
and draw the curved line. The whole line from top to 
bottom is then transferred on to the board that is to be 
used for making the floating rule. This column will have 
its greatest diameter for one-third of its height, and the 
upper portion its entasis. This method is so far defect¬ 
ive as to require the curve to be drawn by hand, a de¬ 
fect, however, obviated by using a column trammel, 
which is used for a column that diminishes with a grace- 


180 


CEMENTS AND CONCRETES 


ful curve from the base to top of the shaft. This trammel 
is made as follows: 

Column Trammel .—A column trammel is simple in 
construction, and when carefully used gives very satis¬ 
factory results, forming a graceful diminished curve 
from the lower diameter to the upper diameter of the 
shaft. Before describing the method of setting out and 
constructing the column trammel, the method of finding 
the point D on Fig. 2 is given on a separate sketch (Fig. 
5) to show the method more clearly. 

Fig. 5 illustrates the method of obtaining the point D, 
on which the centre pin is fixed for the trammel to 
slide on while working. This point also gives the length 
of the radius-rod. This sketch is reduced one-half in 
size to that of Fig. 2a, but the letters correspond to it. 
Having set out the axis or centre line of the column (A 
B) and the base line (AC) (extending the latter indefi¬ 
nitely) as described for Fig. la,, proceed as follows. From 
A as a centre, and from A to B as a radius, describe an 
arc, as indicated by the dotted line; then from the in¬ 
tersecting point at C as a centre, and from C to the 
point at B as a radius (as indicated by the dotted line), 
describe an arc until it cuts the base line at K. This 
done add the distance from the point at A to the point 
at K to the base line, outward from the point at C, which 
gives the desired point D. 

The trammel should be set out on a wall or a clean 
floor. To set it out, first draw a line to the exact height 
of the proposed column, as A B on Fig. 2a, then draw 
a line (indefinitely in length) at right angles to A B, as 
shown from A to D. This line A B is the axis or centre 
line of the column, and the line A D is the base line. To 
construct the trammel, take two rules, each the length of 
the column, and about 2 inches wide, and in* thick; 


METHODS OF WORK 


181 


fix one on each side of the axis of the column, taking care 
to keep them equidistant and parallel to the axis, and 
forming a grooved space about 2 inches wide, as shown 
at a, a, the rules, and b the groove. These rules are 
made thicker than the board intended for the floating 
rule, so as to allow the trammel pencil to run freely 
when marking the diminished line on the board. This 
is shown by the section at Fig. 1. This is as when done 
in a temporary way on a floor, but a better way is to 
fix the rules on a board (a flooring board will be found 
suitable). This makes a permanent groove, and forms an 
easy ground for the sliding block to work smoothly. It 
also allows a greater space for a thicker board for the 
floating rule. 

Fig. 2 shows enlarged details of the groove rules (A, 
A,) the groove (b,) the sliding block (B), with the pin 
(H), the radius-rod (F), with the pencil (G), and the 
board for the floating rule (C), with the diminished 
line. Fig. 1 shows a section of Fig. 2. The letters in 
all figures correspond with each other. Fig. 2a shows 
the whole column with the trammel and finished floating 
rule (C). Make the radius-rod about 2 inches wide, 1 
inch thick and in length a little longer than the distance 
from D to B, and the half diameter of base of the shaft. 
The sliding block (H) is about 4 inches long and equal 
in depth and width to that of the sliding groove (b). It 
should be made smooth, and fit the groove easily, so that 
it will slide freely from end to end when working. In 
the exact centre of the block fix a hardwood pin or a 
round nail (H). This must be fixed exactly over the 
axis of the column, and so fitted that it will run imme¬ 
diately over it from end to end. Bore a hole in the ra¬ 
dius-rod to fit this pin, then from the centre of the pin 
set off exactly half the diameter of the base of the col- 


182 


CEMENTS AND CONCRETES 


umn on the radius-rod, which will give the point for 
the pencil hole (G). At this point bore a hole large 
enough to receive a pencil, which must be tightly held in 
it. At the lower end of the radius-rod cut a slot just 
wide enough to receive the center pin at D. 

A plan of the radius-rod with the slot and centre pin 
is shown at Fig. 3 and a section at Fig. 4. The block 
beneath the radius-rod, in the section is used to keep the 
rod level with the rules and sliding block, as shown on 
Fig. 1. To ascertain the length to cut the slot, place the 
radius-rod along the line A D, and the pencil at the out¬ 
side of the semi-diameter at the base of the column, and 
slide it to its place; mark on the rod where the centre 
pin (D) comes; then place the pencil end of the rod at 
the top diameter, and mark the rod again at the centre 
pin; this will give the length of the pin. Having made 
the trammel, provide a stolit board to form the floating 
rule (cc). This board should be planed on both sides 
and one edge. Place it near the rules a a, keeping the 
planed edge outwards, and parallel with the axis or 
centre line of the column. This allows the planed edge 
of the floating rule to be used as a straight edge to 
plumb by when fixing the top and bottom rims or mould¬ 
ings, which are used as guides and bearings when float¬ 
ing the column. Place the sliding block in position, and 
lay the radius-rod over the center pin, and the pin of the 
sliding block, keeping the rod in a line with D A, tak¬ 
ing care that the pencil is in its true position; then care¬ 
fully move it upwards, and pressing the pencil gently 
upon the board which will give the line for cutting the 
diminishing floating rule. The floating edge is strength¬ 
ened by nailing a strip of sheet iron on the board in a 
similar way to that in which a mould plate on a running 
mould is treated. This is of special use when floating 


METHODS OF WORK 


J83 


diminished fluted columns or pilasters, as the thin and 
sharp edge allows the flutes to be more easily formed. 
The diminished line on the metal plate can also be 
formed with the trammel. 

A column trammel can also be used for setting out 
other diminished floating rules for columns less in size 
than the original one. The only alteration required for 
this purpose is to alter the point D to suit the size of the 
proposed column, and the shortening of the radius-rod. 
It will be seen that the floating rules for both columns 
are made long enough to bear on the base and necking 
mouldings, but it is usual to make them shorter so as to 
bear on cast or run rims or collars, which are fixed at 
the top and bottom of the shaft. 

Constructing Plain Diminished Columns. —Plain 
diminished columns and pilasters are formedwith a 
diminished rule fashioned at both ends to work on the 
necking and base mouldings (termed rims), or on collars. 
The method of making rims and collars, which are used 
as bearings, is as described for diminished fluted 
columns. 

To Set out the Flutes of Diminished Column. —The 
annexed illustration No. 10 elucidates the method of set¬ 
ting out the flutes of a column. Fig. 1 shows the half 
plan of a column; A is the plan of the flutes ai the base, 
and B the plan at the top of the shaft. Fig. 2 shows the 
elevation of the column, with the various parts marked. 
Fig. 3 shows the plan and centres for setting out the 
flutings for the different orders with arrises or with fil¬ 
lets. A fluted column may be divided into twenty, 
twenty-four, or twenty-six flutes, according to the style 
or order. There are two different sorts of flutes used. 
One is worked to an arris, and sunk down in different 
depths, one of which is described by the fourth part of 


184 CEMENTS AND CONCRETES 



Elevation 

___ B. A. 


'ISj 

jj§ 

- 



P L AN 

—Diminished Fi.uted Columns. 


no. 10. 
















































































































































METHODS OF WORK 185 

the circle, one by the sixth, and others by the half 
circle, as shown at 0, D, E, Fig. 3. 

The square or fillet of the second kind is equal to one- 
third part of the flute. It will be seen in Fig. 2 that 
two lines are shown at the top of the flutes. The lower 
one shows how the flutes finish, when the fourth and 
sixth depths are taken, and the top line when the half¬ 
circle is taken together with the fillets. Flutes that 
finish with an arris are usually employed for columns in 
the Doric order, and those that finish wfith fillets are used 
in the other orders. The fillets or lists at the top and 
bottom of the shaft of a column, which serve to divide 
the shaft from the capital and base mouldings, are com¬ 
monly called the upper and lower fillets, and sometimes 
the horizontal fillets, but in architecture they are known 
as “cinctures.” The curved parts at the top and bottom 
of the shaft which are usually curved into the upper and 
lower fillets by a concave curve or inverted cavetto, are 
in architecture termed “apopliygis.” 

Constructing Diminished Fluted Columns .—The 
formation of diminished ‘fluted columns by' means of a 
running mould is an absorbing and vexed topic among 
plasterers, and many ingenious plans have been advanced 
for the construction of hinged and spring running 
moulds, and diminished running rules. I have known 
more than one self-improving plasterer who has ex¬ 
pended a vast deal of time and lime (not forgetting 
plaster) to prove by actual practice the possibility of 
running a diminished fluted column, while others have 
been content to work them by theory, forgetting that an 
ounce of practice is worth a ton of theory. Some men 
thought they had accomplished a feat when they had 
run a single flute with a hinged mould, between two run¬ 
ning rules fixed to form diminution in width, forget 


186 CEMENTS AND CONCRETES 

ting or not knowing that flutes diminish in depth as well 
as width. 

The difference in depth of flutes, at the base and the 
top of the shaft, is shown at A, the base, and B, the top, 
in Fig. 1, illustration No. 10. Running moulds have also 
been made with springs to regulate the diminish in 
depth, but their action was uncertain, and they are also 
too expensive for the purpose. Another form of run¬ 
ning mould was made by fixing wire, catgut, or leather 
on one end of one of the slippers, and on the upper edge 
of the stock, so that the slipper, when being forced up 
the diminished space between the running rules, became 
more angular, or in other words, the slipper on which 
one end of the wire was attached was higher up the 
diminished space than the other slipper, and thus caused 
the stock to cant forward, or be drawn out of an up¬ 
right, and reduce the depth of the flute. The stock in 
this case is connected to the slippers not by hinges, but 
by a pivot inserted at each slipper to allow the stock 
to cant forward when pulled by the wire. This form 
of mould also proved to be too erratic in its working 
to be of useful service. Running moulds having the 
stock connected to a slipper at each side by means of 
two hinges, (termed a double-hinged mould) allow the 
mould to assume an angular or slanting form as it passes 
up the diminished space, thus forming a diminution in 
the width of flute, but it does not form it with a true 
arc all the way. On the contrary, it assumes an elliptical 
form which becomes more and more pronounced as it 
reaches the top of the shaft. 

The nearest approach to perfection in running dimin¬ 
ished flute is performed by means of a running mould 
made with hinged slippers as described, but having the 
mould plate and stock cut through the centre of the 


METHODS OF WORK 


187 


profile, the two parts being then connected by a hinge. 
This form of running mould (termed a “triple-hinged 
mould’’) allows the mould to collapse in the form of a 
V on plan, and the slippers to run level or parallel with 
each other, thus forming each half of the flute alike, and 
at right angles from the centre. Still this has the defect 
of forming the flute without the necessary decrease^ in 
depth. 

A method for diminishing the depth of the flutes is to 
make the running rules with a diminish on face, or 
rather to make them with an increasing thickness towards 
the top ends, so that the mould when running up on the 
increasing thickness will form a corresponding de¬ 
creased depth of flute. When running a fluted column 
by this process, the running rules are fixed flush with 
the face line of the fillets. Only one flute can be run at 
a time, but twelve may be in hand at the same time. As 
there are generally twenty-four flutes in a column, 
twelve rules would be required to keep a couple of 
plasterers going. When the first set of flutes are run, 
the rules are taken off and fixed to run the remaining 
flutes. When all are run, the returned ends at top and 
bottom require to be made good. It will be seen that the 
running rules for this method must be carefully made 
and fixed to ensure true lines and forms. It will be 
understood that a bed or ground must first be formed 
as a guide for setting out and fixing the running rules 
on. This is done with the aid of a diminished floating 
rule. It will also be self-evident +hat the floating rule 
would be more profitably employed for forming the 
entire shaft with the flutes, thus dispensing with run¬ 
ning rules and hinged moulds. This method of running 
the flutes is slow and tedious, but tne worst part is that 
the flutes are not true segments; in fact, the whole of the 


188 


CEMENTS AND CONCRETES 


methods mentioned are more or less a rule of thumb, un¬ 
certain and inaccurate. 

A knowledge of the rudiments of geometry will prove 
that the true form of a diminished and swelled fluted 
column cannot be run with a mould, however ingeniously 
made. This may be proved by cutting a plaster or card¬ 
board disc to the former radius of a single flute, and de¬ 
scribing a line round it on a board. This would be the 
form the mould, when at right angles at the bottom of 
the shaft, would give the flute. Then place the disc in 
an oblique position (the same as the hinged mould would 
be at the top), and project the plans by means of a set 
square on to the board. It will be seen that the mould 
would give the flute an elliptical form. It may be 
further explained by stating that when the mould is 
square at the base, or at right angles with the vertical 
running rules, the form of the flute would be a true 
segment; but when the mould is moved up the dimin¬ 
ished space between the rules, it assumes an oblique or 
slanting position. It gives the flute an elliptical form, 
which increases and becomes more pronounced as it ap¬ 
proaches the necking. It may be said that the pointed 
or elliptical defects can be filled in and worked fair 
with circular hand floats, but this plan necessitates a 
series of hand floats to fit the ever-varying widths and 
depths of the flutes. 

It may seem unnecessary to describe the above meth¬ 
ods, and then to point out their defects. However, the 
methods and defects are given to prevent the rising plas¬ 
terer falling into the same errors, and to enable him to 
resist and rebut the arguments that are so often ad¬ 
vanced by some men, who persistently assert that their 
own particular way (generally one of the methods al- 


METHODS OF WORK 


189 


ready mentioned) is the correct and only way of proper¬ 
ly performing this different but interesting operation. 

It is worthy of note, to show the interest taken in 
this subject that a patent was obtained for a running 
mould and process for forming diminished fluted col¬ 
umns, in 1878, which obtained a provisional protection 
for “improvements in moulds or templates for running 
stucco or cement tapered fluted columns. ’ ’ The follow¬ 
ing is a copy of the specification in extenso:— 

This invention relates to the running of stucco or ce¬ 
ment in forming fluted or other columns, pillars, or pi¬ 
lasters, and similar surfaces, in a more simple, economi¬ 
cal, and expeditious manner than heretofore; and the 
nature and novelty of the invention as applied for run¬ 
ning or making the body part of a fluted tapered col¬ 
umn of stucco or cement, consisting in constructing a, 
short box-shaped template, having two sides joined to¬ 
gether by a back plate outside, with a handle upon it, 
for drawing it up and down the column, and with an 
open space inside the back between the sides open above 
and below, equal to any desired section or segment of 
the column at its base or widest part, into which the 
column is equally divided by narrow longitudinal 
strips of wood, against which the inner edge and end 
surfaces of the sides of the template slide close, so as to 
prevent the escape of the semi-liquid or stucco. A thin 
elastic segmental mould plate is hinged or jointed at its 
ends to the inner faces or edges of the template, formed 
in its inner scraping edge to correspond to the segmental 
curve of the base of the column, with rounded pro¬ 
jections corresponding to the flutes to be formed on the 
column. This plate and its hinges are laid at an angle 
highest at the inner scraping edge, and inclined down¬ 
wards towards the back, leaving a space between it and 


190 


CEMENTS AND CONCRETES 


the back for the free passage or escape of the super¬ 
fluous stucco or cement scraped off the column during 
the ascent of the mould along the column on its longi¬ 
tudinal shaping strips before mentioned. 

4 4 The one end or side of the mould is made to slide or 
contract laterally in slots or other equivalent guides in 
the back of the mould frame as it ascends along the con¬ 
tracting or tapering longitudinal laths, the thin .plate 
bending or yielding down in a curvilinear form on its; 
end hinges before mentioned, so as to bulge inwards while 
bending downwards, and so contract the column in a 
nearly true radical and segmental form from the bottom 
to the top of the column, the angle at which the scrap¬ 
ing mould plate is set on its hinges determining this con¬ 
traction of the scraping centre edge of its segment radi¬ 
cally in a ratio corresponding to the contraction of the 
lengths of the segment and moving sides of the mould, 
which, for large moulds and columns, might be car¬ 
ried and drawn up by handles secured to the tops of 
the ends of the moulds with ropes led up and over pul¬ 
leys at the top of the column, thence down to the hand 
of the operators, so that the mould may be raised and 
lowered at pleasure to form the whole segment of the 
column from the bottom to the top in nearly as simple 
and efficient a manner as plain mouldings are at present 
run by the usual simple edge scraping moulds, one seg¬ 
ment being run after the other in succession until the 
column is finished. 

‘‘For plain or other forms of columns the inner scrap¬ 
ing edge of the mould plate is made to correspond to the 
tapered surface of the column to be formed plain, seg¬ 
mental, or fluted as desired; and for flat, square, or polyg¬ 
onal columns, which do not require a segmental mould 
scraper, this would be made straight, either plain or 


METHODS OF WORK 


191 


fluted, as desired on its scraping edge, and set horizontal¬ 
ly on its hinges, instead of at an angle as described for 
the segmental mould scraper for forming round col¬ 
umns ; and this mould scraping plate in any case is pre¬ 
ferred to be made of thin elastic steel or tempered cop¬ 
per or brass, which would bend and contract the flutes or 
ridges on the surface of the columns or pillars, equally 
and proportionally to the several parts of the column 
over which the mould is traversed. Although the mould 
or template has been described as made with only one 
of its ends movable laterally, it is to be understood that 
both ends or sides may be fitted so as to move in a 
similar manner to suit different kinds of work. 

This patent method would be better understood if it 
had been illustrated. No provision for diminishing the 
depth of the flutes is given in this method. The use of 
flexible metal for diminishing purposes cannot be relied 
on for accurate work. 

Another method for forming diminished fluted col¬ 
umns is thus performed:—Make a single flute in plaster, 
and use it as a mould for casting reverse flutes composed 
of fibrous plaster. After casting as many reverse flutes 
as there are flutes in the proposed column, indurate them 
with litharge oil or paraffin wax. Casts of the necking 
and base, each with about 3 inches of the fluted shaft, are 
fixed on the brick core. The shaft is then laid with 
Portland cement (or other desired cement) and sand un¬ 
til within about one-third of the line of fillets, and 
while this stuff is still soft, take a reverse flute 
(previously oiled) and press it into position, using the 
cement flutes at the necking and base as guides for fix¬ 
ing, and using a diminished floating rule to prove the 
outline. Repeat this process until all the flutes in the 
column are filled with reverse flutes. The intervening 


192 


CEMENTS AND CONCRETES 


spaces or fillets are then filled in with gauged cement 
until flush with the outer surface of the reverse flutes, 
and further regulated with the floating rule. When the 
stuff is set, the reverse flutes are extracted, and any de¬ 
fects in the flutes made good. On the care in fixing the 
reverse flutes and filling in the fillets depends the success 
of this method. 

Diminished fluted columns are also made by casting 
two vertical halves, and then fixing them on the brick 
core. The halves are fixed by means of cement dots, 
which are laid on the core at intervals. (Corresponding 
dots are laid on the interior of the casts. The casts 
are then pressed on the core until the dots meet, and 
both halves are in proper position. The cast work is 
made solid with the core by pouring a thin and weak 
solution of cement and sand into an orifice at the neck¬ 
ing. 

The cement and sand should be mixed in the propor¬ 
tion of one of the former to five of the latter. This 
gauge has sufficient binding power and strength for this 
purpose, and is.not liable to expand or contract in wet or 
dry weather. This process is useful for small work, and 
makes a good job when cleanly cast and neatly fixed. The 
necking with the capital and the base may be fixed be¬ 
fore or after the shaft casts are fixed, according to cir¬ 
cumstances. The shaft casts are best formed in a reverse 
casting mould. 

Another method of casting a diminished fluted col¬ 
umn is effected by making a reverse casting mould. Fix 
it round the core, and pour the gauged material in at 
the top of the necking mould. By using a reverse 
casting mould made with a plaster face and a wood back¬ 
ing, or a mould made in fibrous plaster, the whole 
column with the core can be made in one piece. Hoi- 


METHODS OF WORK 


193 


low columns, composed of Portland cement concrete, 
can be made to carry any weight supported by a stone 
column,.or one constructed with a brick core of equal 
diameter. Cast hollow columns are made by temporarily 
fixing a wood or fibrous plaster core tapered to one end 
to allow it to be withdrawn when the concrete is set. A 
rough wooden or a fibrous plaster hollow core is used 
when casting a hollow column in situ. The core in this 
case is left in. 

After many years’ experience and observation on this 
subject, I am of opinion that the true form of a dimin¬ 
ished fluted column (composed in Portland or similar 
cement, and constructed in situ) is best obtained by 
hand, with the aid of cement rims or plaster collars 
and a diminished floating rule. Most plasterers will 
admit that what can be and is done in stone or wood, 
can be done equally well in cement or plaster. A plaster¬ 
er has one advantage, inasmuch as he can add as well 
as subtract when forming circular surfaces, whereas the 
mason can only subtract. The two methods hereafter 
given for forming diminished fluted columns by hand 
are simple, speedy, and accurate. They are on one prin¬ 
cipal, and each may be used as circumstances require: 
one is termed the “rim method,” and the other the 
‘ ‘ collar method. ’ ’ 

Forming Diminished Fluted Column by the Dim 
Method .—First make models of the half circumferences 
of the astragal or necking and base mouldings, each 
having about 4 inches of the fluted shaft, as shown at 
Fig. 1, the plan and Fig. 2, the elevation, on illustra¬ 
tion No. 10. To make the models, cut a mould plate to 
fit each of the full-sized mouldings, and the required 
size of the shaft, and “horse” them with radius-rods, 
and run a little over one-half of each circumference in 


194 


CEMENTS AND CONCRETES 


plaster, and then cut them to the exact half circumfer¬ 
ence. This done, set out the flutes, then cut them out 
and form the returned ends. The method of setting out 
the flutes on the ends of the models is shown on the plan 
at Fig. 1. A is the plan at the base, and B the plan at 
the top of the shaft. The returned ends of flutes are 
shown on the elevation, Fig. 2. Add the square plinth 
to the base, as shown on the plan at Fig. 1, which com¬ 
pletes the models. Piece mould the models in plaster, 
and then cast as many half astragal and bases as re¬ 
quired. The materials used for the casts must be of the 
same kind as intended for the shaft. The brick or core 
of the column is now cleaned and well wetted, and then 
the astragal and bases are fixed in position, using the 
diminished floating rule to prove if they are central, and 
the fillets finable with each other. Apply a plumb rule 
on the back edge of the floating rule to test if the astragal 
and base are coneentrical and parallel with each other. 
When these half casts are fixed together on the shaft they 
are termed “rims.” The intermediate space on the 
shaft is then filled in and ruled off with the diminished 
floating rule, using the rims as bearings and guides for 
forming the fillet fine of shaft. 

The methods of forming a diminished fluted column 
by the “rim method” is further elucidated by the an¬ 
nexed illustration, No. 11. This shows an elevation of 
the brick core of a shaft with the astragal rim, A and 
the base rim, B, fixed in position. D is the diminished 
floating rule in position for floating the main or fillet line 
of the shaft. The method of using a diminished flute 
rule for the flutes is illustrated in the 4 4 collar method. ’ ’ 

A second diminished floating rule is required to form 
the back surface of the flutes. This can be quickly made 
by laying the first rule flat on the floor, and from this, 


METHODS OF WORK 


195 


with compasses, describe the back line of the Ante on 
another board, which is afterwards cut to the desired 




-Floated Fluted Columns, Kim Method, 
no. 11. 

line. This rule is used as a. long joint rule to form the 
flutes. The rule should be worked with uniform pres¬ 
sure, the man at the top working in unison with the man 
















































































































































































196 


CEMENTS AND CONCRETES 


at the bottom, both working the rule with a circular 
cutting motion. The flutes are fined down by the aid of 
a small float semicircular in section. For extra large 
columns three floats should be used—No. 1 cut to the 
top section, No. 2 cut to the middle section, and No. 3 
cut to the bottom section. The length of the floats may 
vary from 5 inches to 7 inches, according to the height of 
the column. # If the columns are required with a smooth 
surface, the flutes are worked as above, but the floats are 
covered with fine felt, leather, or rubber, and the sur¬ 
face finished smooth with short joint rules or with pieces 
of flexible busks. The cast parts of the shaft, to the 
fillet members of the astragal and the base, should be 
keyed with a drag, so that the whole shaft, from arris to 
arris of the astragal and base fillets* can be fined, thus 
giving a uniform texture and color, and avoiding a sur¬ 
face joint of the cast work and the fined work. 

A modification of this method is as follows:—The 
lower horizontal fillet of the shaft and the base mouldings 
are cast separately, the fillet part being used as bear¬ 
ings for floating the shaft, as already described, and the 
base is fixed after the shaft is fined. This plan is useful 
for some purposes, such as for extra large columns, as it 
gives more freedom for working the shafts and the bases 
are not so liable to get injured while working over them. 

j Running Diminished Fluted Column by the Collar 
Method .—Run a plaster collar about 1% inches wide to 
the diameter of the top horizontal fillet of the shaft. 
The thickness must be regulated according to the space 
between the brick core and the line of fillet. Cut this 
collar in halves and fix them on the brick core, keeping 
the under side in a line and level with the top of the 
proposed fillet of the shaft. Run another collar to fit 
the horizontal fillet at the base of the shaft, and fix the 


METHODS OF WORK 


197 


upper side of this one level with the bottom edge of the 
fillet at base of the shaft. This done, make two plaster 
models of the flutes, one for the top and one for the 
bottom of the shaft, each about 3 inches wide, and in 
thickness according to the brick core, the diameter being 
taken about 1 inch above the returned ends of the flutes 
at the top and bottom of the shaft. These models are 
set out and made as described for the first method, but 
using plaster instead of cement for the casts. The plaster 
casts are fixed in position, and then the brick core is 
laid and ruled off, using the main diminished floating 
rule (and the plain collars as bearings) for forming the 
main contour or line of the vertical fillets, including the 
horizontal or top and bottom fillets of the shaft, and 
using the diminished flute floating rule (and the plaster 
models of the flutes as bearings) for forming the flutes. 
This done, the fluted collars are cut out, the spaces filled 
in and ruled off, and the returned ends of the flutes 
are formed, and then the whole shaft is fined while the 
work is green. The fillet collars are then cut out, and 
the astragal and base mouldings are then fixed, thus 
completing the column. It will be seen that this method 
entirely dispenses with joints between cast and floated 
work on the shaft, and allows it to be fined in one opera¬ 
tion. 

The method of running diminished fluted columns 
with the aid of collars is further elucidated by the an¬ 
nexed illustration No. 12. A C is the top fillet collar, B C 
the bottom fillet collar, and F C and F C are the top and 
bottom flute collars fixed on the brick core of the column. 
D R is the main diminished floating rule in position for 
forming the main contour or fillet line of the column. 
This rule is rebated at the top to allow for a bearing on 
the top as well as on the edge of the collar. This rule 


198 


CEMENTS AND CONCRETES 


also forms the profile of the top and bottom horizontal 
fillets, and the curved parts of the shafts below the top 
fillet and above the bottom fillet. F R is the flute 




Forming Fluted Columns—Collar Method. 


no. 12. 

floating rule in position when forming the flutes. The 
ends of this rule as shown bear on the back surface of 
a flute as indicated by the dotted lines. A portion of the 
astragal moulding, A, with a part of the shaft is shown 












































































































































































































METHODS OF WORK 


199 


so as to indicate the position to fix the fillet collar, A C; 
a portion of the base moulding, B with a part of the 
shaft, is also given to show the position of the bottom 
fillet collar, B. C. It will be seen that these collars form 
fair bed for the astragal and base mouldings, and when 
taken off they leave true joints as indicated by the ar¬ 
rows at A and B. 

A modification of the above methods for forming the 
fillets and flutes is effected as follows:—Fill in the spaces 
on the shaft between the collars in this method—or the 
rims in the former method—and rule them off with a 
main diminished floating rule as already described and 
when the stuff is firm but not set, the positions and forms 
of the fillets and flutes are set out on the floated surface, 
then the flutes are cut out by hand by means of gouges 
and drags, and afterwards fined as already described. 
This system is specially useful for small columns. 

For extra high columns it will be found difficult to 
work a floating rule to form the whole height of the 
column in one operation, in fact, for some columns to be 
seen in cities, which are 20 feet to 30 feet high, and 
even higher, it would be impossible to form them with 
one floating rule. It is therefore necessary to divide the 
column into two or more sections, and cut the floating 
rules accordingly. In this case two or more plaster col¬ 
lars about 3 inches wide, and made to the exact circum¬ 
ference of the column at the point of division, are re¬ 
quired. These collars are then temporarily fixed in posi¬ 
tion to act as screeds, and after the whole surface of the 
column is filled in and ruled off, the collars are cut out 
and the spaces filled in, and then the whole surface 
fined in one operation. Three or even more floats, as 
already described, are required for the fining of high or 
massive columns. 


200 


CEMENTS AND CONCRETES 


Having now briefly reviewed the more or less useful 
methods, and described some of the most useful and 
practical methods, the conclusion to be drawn is, that 
diminished fluted columns are best done by working 
them by hand, with the aid of diminished floating rules 
and cast or run bearings. This first or rim method will 
be found useful for many purposes; but the collar meth¬ 
od, with the addition of intermediate collars for extra 
high columns, is the best for general use. 

Diminished Fluted Pilasters .—Pilasters are said to be 
a Roman invention. They bear an analogy to columns 
in their parts, have the same names and standard of 
measurements, and are diminished and fluted on the same 
principals. When pilasters are placed behind columns, 
and very near them, they should not project above one- 
eighth of their diameter; but if they are from 6 to 10 
feet behind the column, as in large porticoes and per¬ 
istyles, they should project at least one-sixth of their 
diameter. When they are in a line with columns, their 
projection should be regulated by that of the columns. 
When pilasters are used alone as principals in composi¬ 
tion, they should be made to project one-fourth of their 
diameter to give regularity to the returned parts of the 
capitals. The process for forming pilasters is the same 
as for columns. 

Panelled Coves .—Large coves, segmental or elliptical 
on section, having their surfaces panelled with mouldings 
which spring from the back or above a wall or main 
cornice, and finish at or intersect with a beam or other 
moulding at the top or crown of the cove, require to be 
carefully set out and screeded. The floating is done 
from two horizontal screeds made at the top and bottom 
of the cove, and from these vertical screeds are formed, 
and then the intermediate spaces or bays are filled in 


METHODS OF WORK 


201 


and ruled off with a floating rule bearing on the vertical 
screeds. The horizontal screeds are easily made, but the 
vertical ones require special care to insure all being uni¬ 
form in section. These screeds are formed with a tem¬ 
plate cut to the desired section, and about 2 inches thick. 
For large coves they are made with three or more pieces 
of wood. The most correct and expeditious way of 
forming circular screeds is by the “pressed screed’’ 
process. 



Section of Cove Showing Pressed Screed Process. 

NO. 13. 

Pressed screeds are simple and expeditious in con¬ 
struction. They form accurate grounds for floating pur¬ 
poses and fcr running mouldings on circular surfaces. 
The method of forming pressed screeds and floating co^es 
is shown in the accompanying illustration No. 13. This 
shows the section of a cove with the main or wall cornice 
and the crown moulding. F is a nib rule used when 



202 


CEMENTS AND CONCRETES 


running the main cornice. To float this cove for the run¬ 
ning of vertical mouldings, first form the top and bottom 
horizontal screeds (A and B), then form the pressed 
screed. This is effected by temporarily fixing the 
template, G, or by one man holding it on the bottom 
screed, and another man holding it on the top screed, 
while a third spreads and presses the gauged coarse stuff 
until the space between the first coating and edge of the 
template is filled up, then drawing the trowel down each 
side of the template clears off any superfluous stuff. 



-Fig. i. Floating Coves. F*g. 2. Levelling Rule. 
NO. 14. 


The template, which has been previously oiled, is then 
removed, leaving a narrow, but true and smooth screed 
ready for working on. This method gives a truer 
screed, especially in elliptical or long circular screeds, 
than floating or working with a template, because if the 
template is not worked perfectly vertical, the curve of 
the screed is altered and not true. 

The subjoined illustration (No. 14) elucidates the 
method of forming the screeds for floating cove surfaces, 
also for floating segmental, elliptical, or any other form 



































METHODS OF WORK 


203 


of interior and exterior angles in coves. Fig. 1 shows a 
plan of the cove. The letters in this sketch correspond 
with those on the same parts in the section on illustration 
No. 13. The first coating and the various bays, after 
the screeds are made, are indicated by crossed diagonal 
lines at the D’s. The top screed, A, should be levelled 
from end to end and made parallel in depth with the 
crown moulding. Their levelness is tested with the aid 
of a “levelling” rule. The bottom screed, B, should 
be made parallel with the main cornice, so that the pro¬ 
jection of the vertical mouldings will be uniform. The 
vertical screeds, C, are next formed, making the first two 
near the internal angles, then two at the external angles. 
The intervening space is now set out, so that the screeds 
may be 8 to 10 feet apart. The screeds may be formed 
farther apart according to requirements. If there are 
vertical mouldings to be run in the cove, the screeds 
should be made at the sides of the proposed mouldings. 
It is always best to have two or three screeds near the 
angles, so as to give a bearing for the floating rule, R. 
This shows the position of the rule when floating the in¬ 
ternal angle. The external angles on the other side are 
formed in the same way. The distance between the 
screeds used for floating the angles can be regulated ac¬ 
cording to the depth or form of the angle. It will be 
understood that the floating rule must be sufficiently 
long to bear on two vertical screeds, and reach to the 
extreme point of the angle. The floating rule, R, here 
shown is termed a grooved floating rule. This is grooved 
on both sides, as shown by the section, S. 

Fig. 2 shows the elevation of a levelling rule as used 
for levelling dots for ceiling, beam, or crown screeds. 
This is similar to an ordinary parallel rule, but with the 
addition of a fillet, F, nailed flush with the bottom edge 


204 


CEMENTS AND CONCRETES 


to form a ledge to carry the spirit level, L. The level¬ 
ling rule is applied on the dots to test if they are level; 
this is proved by inspecting the spirit-level; if one dot is 
too full it must be depressed until the levelling rule is 
level. 

Diminished Mouldings .—Mouldings that diminish in 
depth or projection as well as in width (termed “double 
diminished mouldings”) are not so common as those that 
diminish in width only. The diminish in width is simple, 
and is obtained by the aid of a “triple-slippered” run¬ 
ning mould and two running rules fixed to form a 
diminished space, as described hereafter. The formation 
of a regular and pleasing diminish in depth greatly de¬ 
pends on the profile of the moulding. A moulding.hav¬ 
ing small members, especially at the sides, is more diffi¬ 
cult to diminish than one having large members, es¬ 
pecially one with plain and deep fillets at the sides. 
Three methods are here given for running double dimin¬ 
ished mouldings on domes, cupolas, or vaulted ceilings, 
or on lower surfaces. These methods give good results, 
especially if a little thought for the requirements of the 
case is bestowed on the designing of the moulding. 

Double Diminished Mouldings, False Screed Method — 
By this method the diminish in depth is obtained by false 
screeds, and the diminish in width by the aid of a dimin¬ 
ished rule, which is fixed on the centre of the profile or 
bed of enrichment. This method is elucidated in the fol¬ 
lowing illustrations. The annexed illustration No. 15, 
shows the section of a vertical moulding on the plaster 
or floated surface of the inside of a dome. C is the 
main cornice from which the inner line of the dome 
springs. The D’s are dots which are used to regulate 
the-diminish of the false, screeds. The various thickness¬ 
es and positions of the dots are obtained by setting out 


METHODS OF WORK 


2G£ 


the full size of the section on a floor or worked out to a 
scale. If the section is elliptical, dots should be placed 
at the points where the transition of curves takes place. 
When the surface of the dome has been floated, the 
diminishing dots, D, are placed at each side of the in¬ 
tended moulding and at their proper positions, begin- 



•Section 'Double Diminished Mouldings— 
False Screed Method. 

NO. 15. 


ning above the main cornice, C, and going upwards m 
rotation but having no dot at the top. The spaces be¬ 
tween the dots are next filled and ruled in, bearing on 
the various dots with the curved rules or templates. 
When ruling the top bay of the screed, the top end dT 
the rule bears on the original floating at the top or ex- 




CEMENTS AND CONCRETES 




EIlevation. 



Elevation Double Dimi¬ 
nished Mouldings—False Screed* 
Method. 



NO. 16. 


false screed. 






































METHODS OF WORK 207 

treme point, this point being the true thickness of the 
screed. 

Illustration No. 16 shows the plan and elevation of the 
w T ork. Fig. 1 shows it in progress, and Fig. 2 when 
finished. The A’s on plan and elevation (Fig. 1) are 
false screeds, the B’s are brackets, while C C indicates 
the diminished running rule. This rule is made as fol¬ 
lows:—First plane one face of a pine board about % 
inch thick, and of sufficient length and width for the 
desired purpose. On this make a centre line from end 
to end. From this centre line set off the width at one 
end, and the diminished width at the other end; then 
extend the diminished width lines from end to end, and 
then plane the running edges to the diminished lines. In 
order tO' allow the rule to bend freely to the curved 
surface, make a series of saw-cuts crossways on the back 
or bed face. The false screeds are made as already de¬ 
scribed. A centre screed for the running rule is made 
by the aid cf a template. This is made with two slippers, 
one on each side, similar to a running mould, so as to run 
on the false screeds, the centre or cutting edge of the 
template being made to the depth of the proposed screed. 
The face surface of the bracket is then laid with gauged 
stuff and finished off by working the template up and 
down. This done, fix the diminished rule, C, on the 
centre of the screed. The running mould; E, on the 
plan is made with the slippers, one to bear on the centre 
screed and against the running rule, and the other to 
bear on the side false screed. The slippers are made 
circular on their running edges, so as to fit the circular 
screeds. A short slipper at the nib gives more freedom 
and ease when running the moulding, and the mould is 
not so liable to cut up the screeds. After the moulding 
is run on both sides, take the running rule off, then cut 


208 


CEMENTS AND CONCRETES 


the false screeds down to the floating, ana make the sides 
of the fillet good, and then fix the enrichment. Fig. 2 
shows the plan and elevation of the finished moulding 
and enrichment. A, on the plan, shows one side of the 
moulding before the false screed is cut off, and G shows 
the screed cut off and the member made good to the 
floating. The amount of diminish from the bottom to 
the top of the moulding is shown at the brackets B and 
B, and by the profiles of the cornice on the plan and ele¬ 
vation. The bed and section of the enrichment is shown 
at F on the plan. As this enrichment is diminished (in 
width and projection) the whole length must be 
modelled. 

Running Double Diminished Mouldings , Diminished 
Rule Method 4 —This is a method which is introduced, 
and is somewhat similar to the first method described. It 
is well adapted for running mouldings, having no en¬ 
richment on the centre of the section, the bed of which 
may be used as a screed and bed for a running rule, as 
used for the first method. By this method the whole 
moulding is run in one operation. The diminish in 
depth is obtained by the use of two running rules 
diminished on the face, or in other words, diminished 
in thicknessL The diminish in the thickness of the 
rules is obtained by setting the full size, as described for 
the false screeds in the first method. A series of saw- 
cuts must be made on the backs of the rules to allow them 
to bend to the circular surface of the dome. These 
rules act in a similar way to the false screed used in the 
first method, with the addition that they form the fillets 
of the outside members, thus avoiding cutting the screeds 
down and making good the fillets. They are also used for 
obtaining the diminish in width. This is effected by 
first making a central line on the bed surface of the 


METHODS OF WORK 


209 


proposed moulding ; then from this line, at each side, set 
out the half width of the moulding, including the bear¬ 
ing parts of the running mould. This is done at the 
widest or bottom end of the moulding, and at the nar¬ 
rowest or top end. Then from these width marks, lines 
are extended from end to end. On these lines, nails are 
inserted from 2 to 3 feet apart, which act as guides for 
fixing the running rules. The inner sides of the rule are 
placed against the outer sides of the nails and fixed, and 
then the guide nails are extracted, thus forming the 
diminished space and bearings. A triple-hinged mould 
with a slipper at each side is used, so that it will close up 
while being run up the diminished space. The stock is 
rebated, so that it will run on the tops and inner sides 
of the rules. The mould plate must be cut to fit the 
section at the greatest width of the moulding, but care 
must be taken that the depth at the outer members is 
the same as proposed for the top. The ends of the inner 
slippers and the adjoining parts of the stock are cut 
so as to leave an open space, to allow both parts to work 
freely when the mould assumes a raking position, as 
shown on illustration No. 17. 

The extra depth of the square of the outside members 
is formed by the running rules. It may here be re¬ 
marked that the thickness of the rules at the top should 
be made about % inch thicker than the depth of the 
square part of the outside members. For example, if 
the depth of the fillets or square part of the outside 
members is 1 inch, the rules should be 1 y 2 inches thick 
at the top. This allows for the requisite bearing for the 
running mould. The ends of the stock that bear on the 
inside of the rules must be rounded off to allow the 
mould to run freely when it closes up while being run 
up between the diminished space. 


210 CEMENTS AND CONCRETES 

The various parts of the running mould are shown in 
the annexed illustration No. 17. Fig. 1 shows the mould 




Elevations and Section of Running Mould 
and Rules for Double_JDiminched Mouldings— 
Diminished Rule Method. 

NO. 17. 

in position at the bottom or widest part of the moulding; 
R, R, are sections of the running rules; S, S, the slip- 


























































METHODS OF WORK 


211 


pers; and H 2 H, the hinges which connect the two 
halves of the stock to the slippers. The hinge which 
connects the mould in the centre is fixed on the other 
side of the stock. Its position is indicated by dotted 
lines. Fig. 2 shows the form of the mould when at the 
top of the moulding. The letters correspond with those 
on Fig. 1. The thin seams at the centre and sides of the 
moulding which are caused by the joint of the mould in 
the centre and by the joint of the mould and the rules 
are cleaned off by hand. This method, like the first, has 
the defect that the actual diminish or the whole depth of 
diminish lies in the fillets of the outside members of the 
moulding. The difference between the diminished mem¬ 
bers and the regular members will be most noticeable on 
the adjoining members, the vertical fillets of the cavettos. 
If this defect should prove offensive to the eye, it may to 
some extent be remedied by working these members down 
by hand, with the aid of planes, gouges, drags, and joint 
rules, after the moulding is run, so as to reduce the depth 
of the fillets, and throw the difference into the cavettos. 
A line should be set out to the desired diminish on the 
fillets to act as guides when working the cavettos down. 

Running Double Diminished Mouldings, Top Rule 
Method .—Running double diminished mouldings by the 
aid of a “ top rule ’ ’ is another method that I have intro¬ 
duced for this purpose. The diminish in width is ob¬ 
tained by fixing two slipper running rules to the de¬ 
sired diminish and a triple-hinged mould as previously 
described, and as shown at Figs. 1 and 2 on the an¬ 
nexed illustration, No. 18. Fig. 1 shows the running 
mould, M, and the slipper rules, R, R, at the full-sized 
or springing end of the moulding, and Fig. 2 shows the 
running mould and rules at the diminished end. The 
diminishing depth is obtained by the aid of a “top rule’* 


212 


CEMENTS AND CONCRETES 


which is fixed on two blocks, one at each end of the 
moulding, as shown at Fig. 3. This shows the elevation 



Elevations, Plan, and Sections op 
•Running Mould and Rules for Diminished 
Mouldings—Top-Rule Method. 

NO. 18. 

of one side of the running moulds at the springing and 
diminished ends of the moulding, also the running rules. 





























METHODS OF WORK 


213 


B is the section of the fixing block at the springing end 
of the moulding, and D is the fixing block at the dimin¬ 
ished end, upon which the top rule, T, is fixed. This 
rule is fixed on the slant, to suit the desired diminish. 
It must be made sufficiently wide to allow a bearing for 
a part of each half of the stock, M, M, of the running 
mould, and also fixed over the joints of the mould, as 
shown at T, Figs. 1, 2, and 3. The top rule being fixed 
on the slant, causes the running mould to gradually cant 
over when it is drawn from its upright position at the 
springing end of the moulding to the diminished end, 
as shown at Fig. 3, thus forming the diminish in the 
depth of the moulding. M a shows the end section of 
the stock in an upright position when at the springing 
end, and M is the section of the stock in a slanting posi¬ 
tion when at the diminished ends of the moulding. The 
dotted lines in .both indicate the parts of the stocks in¬ 
side the slippers, and the angular dotted line at H, H, 
indicates the splayed or cut side of the hinge. S S is 
the outer elevation of one slipper when at each end of 
the moulding, and R is the slipper running rule. It 
will be seen that the running mould at Fig. 1 is some¬ 
what similar to the triple-hinged running moulds pre¬ 
viously described. But there are two important excep¬ 
tions, namely, the hinges at the centre and the two sides 
of the mould. 

The side hinges for this mould must be cut on one side 
and the angles rounded off, leaving only one screw-hole, 
so as to cause less friction, and allow this part of the 
hinge to turn on a screw when fixed on the slipper. The 
use of this will be seen hereafter. An elevation of a 
hinge, before and after it is cut, is shown at Fig. 4. The 
lower hole on the cut half of the hinge is used, because 
the nearer the “turning points” or pivots are to the 


214 


CEMENTS AND CONCRETES 


running ground or screed, as the case may be, the less 
will the bearing edges of the running mould rise when 
the mould cants over. For instance, if the “turning 
points ” were made at the centre of the depth of the 
mould, the bearing edge of the mould would rise from 
the ground in proportion to the cant of the stock. This 
would increase the depth of the lower members (those 
below the pivots or turning points), instead of dimin¬ 
ishing them. This hole must be enlarged so as to admit 
of a short thick screw to give the necessary strength. It 
will be understood that this part of the hinge works on 
the plain part at the head of the screw. 

Having cut the right and left hinges, they are screwed 
on to the stock and the slippers of the running mould, 
keeping the half of the hinge with the three screw-holes 
on the stock, and the cut part with one screw-hole on 
the slippers, as shown at H, H, Fig. 1. It will also be 
noticed that these hinges are fixed at the lower edge of 
the mould. This is done so as to allow the stock of the 
mould to cant from its base for the reason already men¬ 
tioned. When screwing the cut side of the plate to the 
slipper, allow just sufficient play for the hinge to turn 
smoothly but firmly on the screw. The centre hinge con¬ 
necting the halves of the stock, M, M, is formed with two 
pieces of metal plate. The inner ends are rounded off 
to allow them to turn and a circular orifice one-third the 
width of the plate is drilled at the circular ends, and 
then three or more screw-holes for fixing purposes are 
drilled on the other ends. The two plates are fastened 
together with a flat metal ring or with stout copper wire. 
The thickness of this ring is regulated according to the 
size of the orifice, but allowing just sufficient play for 
the plates to turn both ways when the mould assumes a 
slanting and an angular position, as shown at Fig. 2. 


METHODS OF WORK 


215 


An enlarged view of the centre hinge is shown at Fig. 5. 
The centre hinge is screwed on the inner side or profile 
of the stock, as shown at C, Fig. 1. An enlarged view 
of part of the stock at the joint, when inverted for fix¬ 
ing the centre hinge, is shown at Fig. 6. The top and 
bottom edges and the ends of the stock must be rounded 
off, to allow it to cant over easily. The diminish of this 
moulding, both in depth and width, as shown in the illus¬ 
tration, is a little more than may generally occur .in prac¬ 
tice, but this is given to show the various parts more 
clearly, also what to avoid in the amount of diminish 
when using this method. 

The diminishing depth here shown is about two-fifths, 
and the diminishing width about one-third. The dimin¬ 
ishing depth, by this method, should not be overdone, 
because the running mould assumes an angular position 
both on plan and section, therefore it forms the vertical 
parts of the members in a slanting line and the horizon¬ 
tal parts out of a level. These defects become more pro¬ 
nounced at the diminished end of the moulding, as 
shown at Fig. 2. The top member can easily be made 
level and fair by hand, but it would entail too much 
labor to rectify the defects of the other members, there¬ 
fore this method should only be used for small mould¬ 
ings or where the diminish in depth is of a slight nature. 
The seam at the top member, caused by the joint of the 
mould, is cleaned off and made good by hand. 

Cupola Panels and Mouldings .—In order to facilitate 
the setting out and formation of cupola panels and 
mouldings, the method of drawing them is given. This 
will be found very useful in the general setting out and 
construction of cupolas, whether in “solid” or in 
i ‘ fibrous plaster. ’’ Various parts of cupolas and soffits 
of arches (from designs by J. Gibbs, architect, a pupil 


216 


CEMENTS AND CONCRETES 


of Wren, and a great patron of the plasterer’s art), with 
the method of drawing same, are illustrated on plate 11. 
To draw an octagonal cupola, as shown by the plan at 
Fig. 1, take A B (the width of one side of the octagon) 
as the base line. From the centre of this erect the per¬ 
pendicular line D C, then draw the lines C A and C B; 
this will give the triangle ABC, forming the plan of 
an eighth part of the cupola. The profile (Fig. 2) is 
made by the quadrant of circle (ABC) directly over 
the plan. Divide half the base line, A B on plan, into 
seven parts, as here figured, and six of them will make 
two panels; the seventh will remain for the border. The 
same divisions must be marked on the profile over the 
line A B, as follows:—Take for the border at the bot¬ 
tom four parts, as shown in the plan; place them on the 
profile from the base line to No. 1, and draw a line par¬ 
allel to the base line of the plan; measure the length of 
the two central lines marked 2 2, and place it in the 
profile for the second panel. From thence draw another 
parallel line, and measure the length of the two central 
lines at 3 3 in the plan to find the square height of the 
third panel, and so on to No. 8, as shown in the plan 
and profile. 

The elevation or upright side of this octagonal cupola 
(Fig. 3) is made by the following geometrical rule. # 
First draw the base line (A B) on plan even with the 
base line (A B) of the profile; on this erect the perpen¬ 
dicular line (DC) for the centre of the side; then draw 
all the parallel lines as shown by G G, etc. Take half 
the length of each line, figured in the plan, and mark it 
on each side of the middle line of Fig. 3 until the length 
of every panel is fixed. From these lines and points the 
forms or outlines of the panels are taken. The inner 
divisions are brought over to the number of panels con- 



Settinc our and Plastering Cupola Panels and Mouldings, and Soffits of Arches. 

PLATE. IX. 








































































































































































METHODS OF WORK 


217 


tained therein in the same manner as they appear in 
Fig. 3. The same rule is used for setting the side shown 
at Fig. 4. 

With regards to the soffits of arches, if they are 
divided into panels, they must be of any uneven number, 
as shown at K and L, by having a panel in the centre. 
The border must not be more than one-sixth nor less 
than one-seventh part of the whole breadth. The quad¬ 
rant or profile, E F (Fig. 2), on which the panels of this 
semi-circular soffit are divided, will be sufficient to ex¬ 
plain them. A circular soffit of lesser breadth is shown 
at M, and one of greater breadth is shown at N. Sec¬ 
tions of each soffit are shown at the top of the eleva¬ 
tions. 

The method of constructing the plaster work of cupo¬ 
las depends to some extent on the design and size of the 
panels and mouldings. For example, if the diagonal 
panels shown in Fig. 3 were sufficiently large to admit 
of a running mould to run a piece of moulding (on each 
side of the panels) net less in length than the mitres at 
each end, the best method would be to run the four sides 
of all the panels; but if the panels were too small to 
allow a running mould to run the requisite amount of 
moulding, it would be necessary to run a part, and cast, 
or run down, and plant the ether parts. In some designs 
it would be necessary to plant all the mouldings. In 
some cases the panel mouldings, from the base up to a 
third or fourth of the height of the cupola, can be con¬ 
veniently run; but the panels above this which become 
smaller, and are too small to admit of their being run 
wfith economy, should be planted. Another method is 
to run all the diagonal mouldings that spring from left 
to right, as from A to a, in one length from border to 


218 


CEMENTS AND CONCRETES 


border, and then run the intermediate parts of the 
mouldings springing from right to left. 

The intermediate parts may also be run down, or cast, 
and then planted By this method the intermediate 
parts only require mitring, and if they are planted the 
intersections only require to be stopped. If these parts 
are run, the brackets from right to left must be cut 
down at the intersections to allow the running mould to 
pass when running the mouldings from left to right in 
one length. Whichever method is employed, the surface 
must be floated true to the various curves to form a 
ground for the mouldings, whether run or slanted. The 
surface should also be floated sufficiently smooth to act 
as screeds without using gauged putty screeds for each 
moulding. This is done as described for panelled ceil¬ 
ings. The groundwork of the floating is effected by first 
forming a screed on the base border (A B,), and one on 
the top border (at C), and then from these screeds as 
bearings, form two screeds on the side or vertical bor¬ 
ders, thus completing the main screeds, and from which 
the panel surface is floated. Owing to the brackets and 
the form of the panels, it is a somewhat difficult opera¬ 
tion to float all the panel surfaces with a uniform depth 
and curve. It will be seen that a floating rule (cut or 
so constructed to clear the brackets), whether worked 
vertically or horizontally, cannot travel into the angles, 
and float the whole surface. This difficulty is overcome 
by making dots in each angle, or making narrow screeds 
from angle to angle of each panel. The horizontal dots 
or screeds, as the case may be, are ruled off with a gauge 
rule, which is cut to the required depth, and to bear on 
the side screeds. The vertical screeds are ruled off with 
the circular rule, on which pieces of board cut to the 
desired depth and length of the various panels have been 


METHODS OF WORK 


219 


previously fixed. The intervening spaces are then ruled 
off with short rules cut to the angular curves. 

Another and better way is to cut an angular floating 
rule to fit the curve from A to a, and float all the panel 
surfaces in a line from border to border in one opera¬ 
tion. This angular rule is set out in a similar way as 
described for angle brackets. The rules for this or the 
first method must be made to suit the longest line or 
set of panels. After each set of corresponding panels 
in the other sides of the cupola is floated, they must be 
shortened to fit the next set of panels, and so on, until 
all the panels are floated. The mouldings being dimin¬ 
ished in width, are run from a diminished running rule 
fixed on a centre screed in the same way as described for 
diminished dome mouldings. The screed for this method 
is formed by an angular floating rule cut to the angular 
curve, as already mentioned. For some designs the 
moulding may be run with a twin-slippered running 
mould. This form of mould can also be used for form¬ 
ing about one inch of the panel surface. This acts as 
a ground for floating the panel surfaces. When large 
paterae are used, the ground panel surface may be cast 
with them, thus avoiding floating and setting. The oc¬ 
tagonal panels shown in Fig. 4 are formed in a similar 
way to Fig. 1. After the vertical and horizontal mould¬ 
ings are run, the diagonal sides of the octagons are 
planted. Where square panels form the design, the 
mouldings can be run with a radius-rod running mould 
from a centre pin and block. The sections of the soffits 
of the arches are run with a radius-rod running mould, 
fixed on a radius board, and the cross styles or mould¬ 
ings, as shown at K and L, are planted. A small portion 
of the arch should be run to form a ground on which the 


220 


CEMENTS AND CONCRETES 


enrichments may be modelled. Fibrous plaster is well 
adapted for constructing the plaster lining of cupolas. 

Panelled Beams .—When panelled beams have mould¬ 
ings on the lower part of their sides or faces, and on the 
soffit to form a sunk panel, they may be run in two parts. 
Screeds are formed on the two sides, and one in the 
centre of the soffit. If the mouldings on the sides have 
more girth or are larger than the portion on the soffit, 
they may be run from rules fixed on the side of the beam, 
with the nib bearing on the style or on the soffits. If 
the style and mouldings on the soffit are small, the mould 
is made to run the face, style, and soffit moulding in one. 
If the styles are broad, the moulding on the sunk part 
of the soffit is run from a parallel running rule fixed in 
the centre of the soffit, thus forming a double rule to run 
each side of the sunk moulding. The latter way is most 
generally used. The end or other mouldings required 
for panelling the soffit are run down and planted. 

All beams of any length should always have a camber, 
not only to allow for any settlement that may take place, 
but to make it more pleasing to the eye. A beam dead 
level and straight has the appearance of sagging in the 
centre. This may be termed an optical illusion. 

Trammels for Elliptical Mouldings .—It may at once 
be pointed out that an ellipse and an oval are not the 
same. Both ends of an ellipse are similar, and an oval 
is egg-shaped, one end having a greater curve than the 
other, therefore the term oval moulding or panel is 
scarcely correct when applied to the following illustra¬ 
tions. This term, however, is best known and generally 
used by most workmen in the building trades. The term 
“ elliptical ” is generally applied by plasterers when re¬ 
ferring to mouldings where the whole ellipse is not car¬ 
ried round, such as for mouldings or elliptical arches, 


METHODS OF WORK 


221 


windows, etc.; and the term “oval,” where the whole 
figure is completed, such as panels (elliptical on plan) 
formed on walls or ceilings. In consideration of the 
common usage of these terms, they will here be used in 
describing the setting out or working of same. 

Trammels are often used for running oval pane), 
mouldings, and for forming the lines when setting out 
oval templates. Trammels are made of wood or metal. 
A simple way to make a tram¬ 
mel for small work is to sink 
two grooves at right angles in 
a hardwood board (termed the 
plate), about 7 inches long, 

5 inches wide, and 1 inch 
thick. The grooves are about 
1-2 inch deep and 1-2 inch 
wide. Two hardwood pins are 
then made to fit the grooves. 

They have collars to bear on 
the surface of the plate. The 
upper part is made round to 
fit the centre holes of the rod. 

The subjoined illustration No. 

19 shows a template and 
various sorts of template pins. 

Fig. 1 is a view of a template, 
with the two pins, rod, with the 
running mould attached in 
position, and a part of a moulding. Fig. 2 shows various sec¬ 
tions of pins. A is the section of the pin as used in Fig. 1, 
and C is the plan of the pin at the intersection of the 
grooves. B is the section of a dovetailed pin used for 
another form of trammel. The rod is made to any tie^ 
sired length, so that it may serve for various sized ovals 




-Trammels. 
NO. 19. 



222 


CEMENTS AND CONCRETES 


The average size for this kind of trammel is about 1 foot 
6 inches long, 1 inch wide, and 1-4 inch thick. A series 
of holes 1-4 inch in diameter (to fit the head of the pin) 
is made about 1-8 inch apart on the flat side. The first 
hole is made near one end of the rod, and continued 
down the centre for about 15 inches, leaving the blank 
space for screwing on to the running mould. A pin is 
now laid into each groove, and the size of the desired 
oval is obtained by regulating the length of the rod at 
each diameter by means of the holes. The pin in the 
short groove is the point from which the length of the 
oval is taken, and the pin in the long groove for the 
width. The trammel is fixed on the running board by 
means of two or more screws, as shown. This size of 
trammel can only be used for oval mouldings from about 
10 inches to 36 inches at their longest diameter, there¬ 
fore larger sizes are required for larger ovals. 

A trammel for running large ovals (say from 6 to 10 
feet at the major diameter), if made solid, as shown in 
Fig. 1, would be too heavy and cumbersome for fixing 
on ceilings where the mouldings are run in situ. A 
lighter kind termed a “cross” template, is made as fol¬ 
lows :—Cut three flooring boards, one a little less in' 
length than the longest diameter of the proposed oval, 
and two less than the short diameter. Lay them down 
on a floor in the form of a cross (similar to the grooves 
in Fig. 1), and fix and brace them together. Four angu¬ 
lar braces will hold them together, and allow the whole 
to be fixed on the ceiling. On the centre of this ground 
make two lines at right angles to each other, and from 
these set out the width of the desired grooves at the ends 
and intersections, and then fix wood fillets, each about 
one inch thick and two inches wide, to the marks, thus 
forming the grooves. In order to prevent the pins drop- 


METHODS OF WORK 


223 


ping out of the grooves when the trammel is fixed face 
downward on the ceiling, the inner sides of the fillets 
should be splayed so as to receive dovetailed pins, as 
shown at B, Fig. 2. This may also be effected by fixing 
running rules on the fillets so as to overlap about 1-4 
inch, over the groove space, thus forming rebated or 
square grooves. The pins are made with shoulders to 
fit tbe grooves. In both modes a 1-inch pin must be in¬ 
serted in the trammel pm to prevent the rod dropping. 

A strong, accurate, and permanent trammel can be 
constructed entirely with metal. To make this, procure 
a sufficient length of metal tube, about 1-2 inch in diam¬ 
eter, having a slot about 1-8 inch wide, cut longitudi¬ 
nally. Cut the tube into four pieces, mitring the inter¬ 
sections, and fix and brace them together in the form of 
a cross, as already mentioned. A pin made to fit the slot, 
fixed in a bail made to fit the tube, completes one of the 
sliding pins. The rod may be made of metal or wood, 
but the latter gives more freedom for changing the size 
for different sized cvals. 

Various methods are employed for running oval panel 
mouldings on ceilings. The most useful are by means of 
trammels, or wood or plaster templates. A trammel is 
a good instrument for running oval panels where the 
mouldings are net wide. Wide mouldings (say over 1 
foot) cannot be run true or uniform in width in one 
operation with a trammel, because the running mould, 
which is fixed on the end of the rod of the trammel, 
assumes a raking position' when it is between the right 
angle points of the major and minor diameters of the 
oval. This raking position takes place at the four joints 
or change of curves of the oval, and is more pronounced 
in extra wide mouldings. This difficulty is overcome by 
running the mouldings in two parts, using a trammel 


224 


CEMENTS AND CONCRETES 


mould for running the first or inner part, and a run¬ 
ning mould (horsed to run on the run part) for running 
the second or outer part. This is effected by dividing 
the section of the moulding into two parts, taking care 
to make the joint at the side of a fillet or in the center 
of a flat member at the outer side of the part to be run 
with the trammel mould, so as to allow for a good bear¬ 
ing (wide and strong) for the slipper of the running 
mould used for running the second part. The running 
mould for the first part is fixed on the rod of the tram¬ 
mel as already mentioned. The running mould for the 
second part is horsed with a circular slipper cut to fit 
the curve of the first moulding. If the oval has quick 
curves, a slipper with two pins will give the best re¬ 
sults. 

If there is an enrichment in or near the center of the 
moulding, run the moulding in three parts, using the 
bed of the enrichment (which is run with a trammel 
mould) as a center running rule for running the outer 
and inner parts, which are run with circular or pin- 
slippered running moulds, as already described. It will 
be seen that by using either of these three methods, wide 
mouldings for oval panels can be run uniform on width; 
the trammel mould giving the form of the oval to the 
first part of the moulding, or to the center running rule, 
and the curved slippered running moulds giving the de¬ 
sired uniformity of width to the full section of the 
moulding. Most forms of oval panel mouldings are best 
run with templates. When run with trammels, or with 
radius-rods, the running mould is apt to jump and cause 
cripples at the junction of the major and minor diam¬ 
eters. 

Templates for Running Elliptical Mouldings .—The 
true form of an ellipsis can only be derived from the 


METHODS OF WORK 


225 


diagonal cut from the cone or the cylinder, and the near¬ 
est approximation to this curve must be obtained by 
continuous motion. There is no other instrument so 
well adapted for effecting this purpose as a trammel. 
For a true ellipsis, make the distance from the outer end 
of the rod to the nearest point or centre pin equal to 



Template and Pin-Moui.d for Running 

Elliptical Arch Mouldings, 
no. 20. 


half the shortest or minor diameter of the ellipsis, and 
from the centre pin to the outer pin equal to half the 
longest or major diameter. This shows the use of a 
trammel for setting out the lines to make a template for 
this form of ellipsis. 

The subjoined illustration No. 20 elucidates the method 
of setting out another form of ellipsis; also an oval hav- 



























226 


CEMENTS AND CONCRETES 


ing its major axis one-third greater than its minor. This 
also shows the template and a pin running mould in posi¬ 
tion for running an elliptical arch moulding. The 
template (Pig. 1) is made to extend below the springing 
line of the arch, so as to allow the mould to be run down 
to the spring of arch and save mitring. The template 
for running the arch extends to the shaded part; but 
to utilize the space the curve has been continued round 
to show a method of setting out a template from which 
an oval moulding can be run, the oval having its major 
axis one-third greater than its minor. The method of 
setting out is as follows: First draw the line AB, the 
greater diameter, to the desired length; then bisect it, 
and erect the perpendicular line CD; this being the 
lesser diameter, is made a third less than the line AB. 
Then bisect each half of the line, which will divide the 
line AB into four equal parts and give the centres E, E, 
which are the centres for describing the ends, as from 
F to F, and FI to F2. Then from the centres C and D 
describe the flat curves from F to FI, and from F to F2, 
which complete the oval. It is, however, better to set 
out this template by the trammel, as the junction of the 
segments of the circles always has a more or less crip¬ 
pled look. 

Fig. 2 shows a “pin-mould” in position when run¬ 
ning an elliptical arch moulding. This mould is pro¬ 
vided with two hardwood pins inserted into the bearing 
face of the slipper. The pins bear on the edge of the 
template, and owing to their position, and being apart, 
allow the mould to take any change of curve without 
“jumping.” 

Before running elliptical mouldings on arches or win¬ 
dows, the centres and running rods should be tested, so 
that the mouldings will intersect accurately, and so avoid 


METHODS OF WORK 


227 


jumps at the change of curves. All centre pins should 
be level with each other, and equidistant from the centre 
of the arch or window. The outline and intersections of 
the proposed moulding can be tested by temporarily fix¬ 
ing a pencil on the outer and inner profiles of the run¬ 
ning mould, then working the mould over the screeds, 
so that the pencils will form two lines. I have heard of 
a three-centered elliptical hood moulding being run over 
a window with what is called a “bolt radius-rod.” This 
rod is made in two parts and connected with a hinge, 
and held straight when running the long diameter with 
a bolt and sockets where fixed at the joint. The run¬ 
ning mould is fixed on one end, and a centre plate on 
the other in the usual way. The long diameter of the 
moulding is run first, and when the radius-rod reaches 
the change of curve the bolt is drawn back, and the short 
diameter of the moulding run with the short part of the 
radius-rod. A nail is inserted in a board which is pre¬ 
viously fixed in the window opening. The nail must be 
fixed in a line with the change of curve so as to stop 
the radius-rod, and hold the long part in position while 
the short part is working. The same operation is re¬ 
peated for the other side of the work. It is needless to 
say that this method is far too complicated to be serv¬ 
iceable for general purposes. - 

Templates are used for running most forms of ellip¬ 
tical panel mouldings. Plasterers may make their own 
templates or running rules by using fibrous plaster casts 
as a substitute for wood. This is effected by first set¬ 
ting out a quarter of the proposed oval panel, then cut 
out or run a temporary plaster running rule to fit the 
inner line, allowing a space for the slipper of a running 
mould. Cut a reverse running mould to the section of 
the proposed fibrous plaster rules (say about 1 inch thick 


228 


CEMENTS AND CONCRETES 


and 3 inches wide), then run the quarter length of the 
oval, and after making true joints at the ends, cast four 
fibrous plaster quarters, and then lay and fix them re¬ 
versely, thus completing the full oval template or run¬ 
ning rule. The full oval running rule can also be run 
in situ and in one operation. This may be done with 
a trammel or with radius-rods, according to the form 
and size of the panel. Strong and stiff gauged plaster 
or a strong white cement, should be used for the run¬ 
ning rule, to enable it to resist the friction of the run¬ 
ning mould while running the moulding. Radius-rods 
are more often used for setting out the lines for oval tem¬ 
plates than for running the mouldings. Circular mould¬ 
ings—vertical, horizontal, or angular—run off circular 
grounds require special running rules, so that they will 
take or bend to the double curvature. For this purpose, 
cane, flexible metal pipes, and wooden rules, having series 
of saw-cuts on the backs and sides, have been used, but 
cast fibrous plaster rules or a jack template are more 
suitable for most of these purposes. Template can also 
be made by means of a plasterer’s oval. 

Plasterer’s Oval .—The subjoined illustration (No. 21) 
elucidates the setting out of this form of oval to any 
given size, also the method of forming two oval mould¬ 
ings from two circle mouldings. The ovals are formed 
by running two circular mouldings in plaster, the diam¬ 
eter of one being exactly double that of the other. Each 
circle is cut into four quadrants or quarters. Two of the 
quadrants of the larger circle form the sides of one oval, 
and two quadrants of the smaller circle form the ends, 
the four segments making a fairly good oval. The re¬ 
maining segments constitute another oval of similar size 
and shape. The method is simple and speedy, and it 
can also be employed for the formation of elliptical 


METHODS OF WORK 


228 



N 

o 

£ 


























230 


CEMENTS AND CONCRETES 


mouldings on arches, doors, or windows as well as for 
oval panel mouldings. The formation of ovals by this 
method has been employed by plasterers for genera¬ 
tions, but owing to the want of a definite rule for set¬ 
ting out this form of oval to any given size, its use has 
been somewhat' limited. To meet this want, I have in¬ 
vented a method which can be adopted for most pur¬ 
poses, and which I give here for the first time. For 
want of a better name we have called this a ‘ ‘ Plasterer’s 
Oval, ’’ for the reason that plaster lends itself ipore read¬ 
ily than any other material to the formation of circular 
mouldings. No one in the building trades can form a 
circle or an oval moulding so quickly and accurately as 
a plasterer. T?he. method of setting out and of con¬ 
structing this form of oval is as follows: To set out an 
oval to a given size, the greater diameter being given. 
Take this greater diameter as a base to determine the 
required diameters of the large and small circle mould¬ 
ings, M and N, Fig. 2. Let the line A B, Fig. 1, be the 
given diameter, say 3 feet; on this form two squares, 
each according to their diameter would be 1 foot 6 inches 
by 1 foot 6 inches, as shown at C D E F and FGHC; 
then draw diagonals in each Square as at C E and D F 
and C G and ]jT H and at their intersections 1 and 1 as 
centres draw the circles 1 K and 1 K. The radius in this 
example would be 9 inches. The quadrants M and M 1 
correspond with the same letters in Figs. 2 and 3, and 
they form the tjwo ends of the oval. After this take C as 
a centre, and with a radius from C to 0 at E or G de¬ 
scribe that part of the circle L from 0 L 0, which forms 
the upper side!of the oval; now take F as a centre, and 
with the same radius describe the lower side, joining K K 
at 0 and 0, thus forming the plan of the oval as shown 
by the line A L B, and the dotted line below C. It will be 


METHODS OF WORK 


231 


seen that the respective centres to describe this figure 
give the centres and diameters to run the two circle 
mouldings from which the ovals are formed. 

To construct the oval, first make a running mould to 
the desired profile, using a radius-rod in the usual man¬ 
ner, for running circles on the flat. Before running the 
mouldings, set out two lines at right angles on the mould¬ 
ing board, taking care to extend the lines a little be¬ 
yond the outline of the large circle, as shown by the 
dotted lines (Fig. 2). The extended parts of these lines 
act as guides for cutting the moulding, into exact quad¬ 
rants. The intersection of them is the centre from 
which both circles are run. Apply the running mould, 
and turn it round, so that it leaves a faint mark on the 
running board to indicate the width of the moulding to 
be run. The width can also be marked by the aid of a 
pencil, holding it at the outside member, and turning the 
mould round, repeating this operation on the inside mem¬ 
ber. On this space drive in eight tacks, two in each 
quadrant, leaving the heads projecting about y 2 inch. 
The object of these tacks is to prevent the moulding 
from lifting owing to plaster swelling, or from moving 
round while being run. Cover the tacks with clay to 
allow the moulding to be freely taken up after it is run 
and cut. The moulding is then run in the usual way, 
and is cut into four quarters, or quadrants. This is 
done by applying two set-squares, one inside and one 
outside of the moulding; and at one of the quarter lines 
lay a straight-edge over the moulding and against the 
set-squares. The moulding can then be marked or sawn 
at the proper place and angle. The dotted or quarter 
lines divide the mouldings into quadrants, and give the 
angles for cutting them. 


232 


CEMENTS AND CONCRETES 


The use of extending the lines beyond the moulding 
will here be seen. A part may be obliterated while the 
moulding is being run, but the extended part will af¬ 
ford a correct guide for the outside set-square. If the 
quadrants are cut fine, square, and clean, the joints will 
be scarcely perceptible when the four segments are 
placed together. When this circle is cut and taken off 
the board, the radius has to be altered to exactly one- 
half of the large circle, and the small circle is run and 
cut precisely in the same way as the large one. The four 
quadrants can now be fixed to form an oval, as shown 
in Fig. 3. If a quantity of oval mouldings be required, 
a casting mould can be taken off this oval in which they 
may be cast. It will be seen that the quadrants M and 
N 1 form the sides of the oval in Fig. 3, and the quad¬ 
rants M and M 1 form the ends. It will also be seen that 
after completing this oval there are four quadrants left 
to form another oval. If but one oval is required, run 
only one-half of each circle, allowing a little space 
beyond the centre line, so that a square and clean joint 
can be cut. A thin saw with fine small teeth should be 
used for this purpose. 

Fig. 3 shows the four segments of the moulding in 
position forming the oval. In this figure the moulding 
is struck on the outside of the setting-out circle line, as 
shown in Fig. 1, but the moulding in Fig. 2 is struck on 
the inside of the setting-out lines. This is simply to 
show that the same centres can be used for mouldings 
struck on either side of the lines. A mould for casting 
oval mouldings, also templates, can also be made by the 
above process. For this purpose a reverse running 
mould must be used for running the two circles. A 
plaster piece mould for casting oval mouldings that are 
undercut may also be formed by this method. In this 


Circular Mouldings on Circular Surfaces. 

Fig. i.—Elevation of SmaIl Cove, with Sections. 

Fig, 3.—Section of Large Cove, with Section and Elevation of Main Cornice. 

Fl,ath Hi. 

































































































































































































































































































- 













5 






M 

W 

♦ 








‘ *. 4 


















II 


















- 



































































METHODS OF WORK 


233 


case the running mould must be made and used as de¬ 
scribed for ‘ ‘ reverse moulds. ’ ’ 

Coved Ceilings .—Coves to ceilings are of various 
heights, as cne-third, one-fourth, one-fifth, &c., of the 
whole height. The form of the cove is generally either 
a quadrant of a circle or of an ellipsis, taking its rise a 
little above the cornice, and finishing at the crown or 
other moulding. If the room is low in proportion to its 
width, the cove must likewise be low; and when it is 
high, the cove must likewise be so; by which means the 
excess of height will be rendered less perceptible. An 
example of two coved ceilings (from designs by James 
Gibbs) are shown is the annexed illustration No. 22. 
Fig. 1 shows the plan and elevation of a coved 1 ceiling, 
with circular windows between the groins. Fig. 2 shows 
the plan and elevation of a coved ceiling, the design of 
which is less intricate than that of Fig. 1. The curve 
of this cove is a quadrant of a circle, as shown by the 
section at the side. The plans will enable the section 
of each design to be understood, and vice versa, and the 
whole will render the method of constructing coves and 
circular mouldings on circular surfaces (which is given 
hereafter) to be more clearly understood. The external 
and internal angle mouldings in these coves may be 
formed with a jack template or as described for coves. 

Circle Mouldings on Circular Surfaces .—The accom¬ 
panying illustration, Plate III, is given to elucidate 
various methods of running circular mouldings on cir¬ 
cular surfaces, shows the elevation of a cove suitable for 
an aquarium or marine hall. The external angle rib 
moulding, C, and the panel rib moulding, D, spring from 
the top or weathering of a main moulding, and intersect 
with a horizontal or crown moulding at the top of the 
cove. The section of the horizontal moulding is shown 


Fig-t 


234 


CEMENTS AND CONCRETES 



—JDlans and Elevations, of Coved Ceilings. 
No. 22. 
















































































































































































































































































































































































































































































































METHODS OF WORK 


235 


at G, and the section of the panel moulding is shown 
above D; the section of the external rib being of course 
double that of the panel moulding. Where circular or 
straight mouldings intersect with each other, it is ad¬ 
vantageous in most cases to run the circular mouldings 
first, so that the whole of the moulding can be run, 
and leave the intersection to be mitred on the 
straight part, which is naturally the easiest part. In 
some examples it is not advisable to run the circular part 
first. For example, if the crown or horizontal moulding,* 
as shown at G, Fig. 1, was the lower part of a large 
crown moulding made to intersect with small cove 
mouldings, it would be best to run the straight moulding 
first, and then cut away as much of the straight mould¬ 
ing as will allow the nib of the running mould to pass 
while running the circular moulding. For the section 
in this example there would be very little mitring to do, 
as it would simply be a butt mitre up to the back of the 
circular mouldings. The external rib moulding, C, is 
best run with a jack template. The circular panel 
mouldings (one-half of a moulding is shown at D) can 
be run by two methods. By the first, the moulding is 
run in three parts, using a sledge-slippered running 
mould fixed on a hinged radius-rod, and the two straight 
parts are run from running rules. By the second 
method, the whole moulding is run at one operation by 
using a fibrous plaster template, made as already de¬ 
scribed. 

Forming Niches .—Niches are recesses formed in walls, 
sometimes for the purpose of placing some ornamental 
object in them, such as statues, vases, &c., and they are 
often constructed in thick walls in order to save mate¬ 
rials. The plans or bases of niches are generally semi¬ 
circular, but some partake of all the segments under a 


236 


CEMENTS AND CONCRETES 


semicircle, while others are elliptical, and in a few in¬ 
stances they are square or rectangular. The elevations 
of niches are generally in accordance with their plans, 
but variations from this rule are sometimes met with. 
The crown or heads of niches are generally plain, but 
they are sometimes enriched with scalloped shells, &c., 
or panelled with mouldings. With respect to the pro¬ 
portion of niches, there is no fixed rule, but the general 
one is twice and a half their width for their height. 
Various methods are employed in the formation of 
niches. The crowns of circular niches are generally run 
with a mould, because being circle on circle and small 
in surface, it is difficult to finish them true and smooth 
by hand. 

The accompanying illustration (No. 23) elucidates 
two methods of forming semicircular niches with the aid 
of running moulds. Fig. 1 shows the elevation, and Fig. 
2 the section of the crown and a part of the body of 
niche, with the centre-boards and moulds in position 
when forming the crown of the niche. Fig. 4 shows the 
section of the body of the cove, with the mould in posi¬ 
tion when forming same. By the first method the niche 
is formed in two operations, and by the second method 
it is formed in one operation only. For the first method, 
cut a running mould to the section of the niche, as shown 
at B, Fig. 1, then fix it on the centre board, A, with two 
hinges, keeping the upper surface or mould plate level 
with the top edge of the centre board, as shown on the 
section of the niche, Fig. 2. This also shows the end 
section of the centre-board and the mould, with the 
mould plate and a hinge. The dotted line indicates the 
distance the mould travels. After this, fix the com¬ 
bined centre-board and mould on the wall, taking care 
that the top edge of the centre-board is level and ex- 


METHODS OF WORK 



Forming Niches with Running Moulds. 

NO. 23. 














































































238 


CEMENTS AND CONCRETES 


actly at the springing of the crown, C. The face of the 
wall must be floated plumb, and an allowance made by 
means of dots for the thickness, of the setting coat be¬ 
fore the centre-board is fixed. After the crown is fin¬ 
ished, the centre-board and running mould is taken off 
the wall and separated. The mould is then horsed with 
two slippers to allow of its running the body or vertical 
part of the niche. The mould works on a running rule 
fixed on one of two screeds which are formed on the face 
of the wall, one on each side of the opening. Care must 
be taken that the screeds are plumb with the centre-board 
dots. Fig. 3 shows an elevation of the mould when 
horsed. B is the mould, D is a connecting board on 
which the mould is fixed by means of the cleats, C, C, 
and F, F, are the slippers. Fig. 4 shows an end section 
of the horsed mould in position when running the body 
of the niche. The base is finished by hand. 

By the second method the niche is run in one opera¬ 
tion, as already mentioned. This is effected by cutting 
a running mould to the vertical section of the niche, then 
fixing a pivot at the bottom and a bolt at the top. A 
wood block, with a socket to fit the bolt on the mould, is 
let into the face of the wall at the top of the niche, and 
temporarily fixed, then another block with a socket to fit 
the pivot of the mould is fixed at the bottom of the 
niche. Care must be taken that the sockets are plumb 
and in a line v/'.th the centre of the niche, also that they 
are in a line with the face of the wall, so as to allow 
the mould to form a true semicircle with perpendicular 
arrises. Place the pivot of the mould in the socket, and 
push the bolt up and secure it, and the mould is ready 
for working. 

Fig. 5 shows a section of the niche with the mould in 
position. A is the mould with the pivot and bolt, and 


METHODS OF WORK 


239 


B, B, are the socket blocks. A plan of the niche and 
mould is shown at Fig. 6. This also shows the plan of 
the pivot bicck, and a board which is sometimes used to 
secure the block. The dotted line indicates the dis¬ 
tance the mould travels. When there are splays or beads 
on the angle of the niche, the crown part is run with a 
radius-rod mould from a centre-board, and the vertical 
parts with a “twin-slipper running mould” on running 
rules fixed on the wall screeds, or with a nib running 
mould on a slipper and a nib running rule. 

The vertical parts of the beads or splays may also be 
run with the mould shown in Fig. 3. For this purpose 
two plates cut to the desired section must be fixed on the 
mould, one at each side. The crown part is run with a 
radius-rod, as already mentioned. The crown surface 
and the angle moulding can also be run in one operation. 
This is effected by cutting a mould plate to the section of 
the moulding, including the section of the crown sur¬ 
face, then horsing it with a slipper to run on the wall 
surface, and a pivot to fit a socket formed in a centre¬ 
board, or with a radius-rod to work on a centre-board. 
A pivot will be found most suitable for small work and 
a radius-rod for large work. In either case they must 
be fixed on the centre of the mould, so as to be in a line 
with the mould plate. After the crown is run, the mould 
plate of the crown surface is cut off, and the remaining 
part of the mould used for running the vertical mould¬ 
ings. 

In some designs a small moulding, such as an impost 
moulding, is carried round the body surface of the niche, 
and in a line with the springing of the crown. This 
moulding can be run in a similar way as shown at Fig. 
5, or by fixing a flexible wood or a plaster running rule 
on the body of the niche for the mould to run on. 


240 


CEMENTS AND CONCRETES 


The crowns of niches that are parallel with small 
mouldings are best executed by making a model of the 
design, then moulding it and casting, and fixing as many 
as are required. In niche crowns that are enriched 
with shells, foliage, &c., the enrichment should be cast 
with the crown surface as a background. Fibrous plas¬ 
ter is well adapted for the construction of niches. For 
this purpose a reverse casting mould should be employed 
for forming the casts. This is made by cutting a re¬ 
verse running mould to the section of the niche, and after 
a sufficient length of the body is run, cut the mould in 
half and run the crown. Then fix it on the end of the 
run body, and then fix rules at the sides and ends to 
form fences and rims, thus completing the casting 
mould. 

Any of the above methods for forming niches with 
running moulds can be advantageously used for forming 
the body and crown of the Ionic niche when such is re¬ 
quired. 

Running an Elliptical Moulding in Situ. 

In No. 24 a method of running an elliptical curve with 
a trammel is shown. Fig. 1 represents the front eleva¬ 
tion of the trammel mounted and in working order, and 
Fig. 2 is a section of the same. 

Take two floor boards, B, long enough to reach to the 
springing line of the arch, and nail them on the back of 
two lengths of 5 in. by 2 in., A, which, as shown may be 
somewhat longer. Fix these up inside the jambs of the 
opening, taking care to see that they are perfectly up¬ 
right, and keep them the thickness of the trammel boards 
(which is 1 in.) back from the face of the opening on 
which the architrave is to be. Then cut three pieces of 


METHODS OP WORK 


241 


5 in. by 2 in., C, tight in between and secure them in 
place with 3 in. cut nails, taking care to see that the 
bottom side of the top one is above the springing line. 
Then prepare the trammel boards, D and E, 6 in. by 1 



NO. 24. 

in., and cut the slots, which are % in. wide and of a 
length which may be easily ascertained by simple geom¬ 
etry. Halve the boards together at the joint and fur¬ 
ther secure them by screwing a plate of the thickest sheet 
zinc obtainable on the back, as per Fig. 3. Nail the 


























































242 


CEMENTS AND CONCRETES 


boards up as shown, keeping the horizontal slot central 
on the springing line and the vertical slot exactly in the 
centre of the opening, and be most particular to see that 
the whole lot is perfectly upright and level. Next pre¬ 
pare the trammel stick, 2 in. by 1 in., and mount the 
mould on the top in the usual manner, as shown. Then 
insert the pins in holes bored in the stick and secure by 
a screw through the edge. Have them just thick enough 
to work comfortably in the slots, and keep the centre of 
the pin XI, the distance of the rise, and the centre of 
the pin X2, the distance of the half span from the bot¬ 
tom member of the architrave. All the timber may be 
deal except the pins, which must be of some kind of hard 
wood. If well made and used with care this trammel 
ought to serve many times; the pins, of course, needing 
adjustment for arches of different size. 


MISCELLANEOUS MATTERS. 


Depeter .—This is a sort of a rough-cast, and consists 
of forming a fair surface with coarse stuff or Portland 
cement. As soon as laid a hand-float is parred over the 
surface a few times to give it an even and uniform tex¬ 
ture, and whJ 1 '* it is soft, pressing in by hand, small 
pieces of hard coal, broken bottles, pottery, bricks, shells, 
stones, pebbles, or marble. The design may be varied and 
enriched by using various colored pieces in forming mar¬ 
gins, bands or other ornamentation. On the contrast of 
colors and the broad bands depends the effect of this 
class of work. A combination of “Depeter’’ and rough¬ 
cast may be used with excellent effect. 

Sgraffitto .—Sgraffitto or “graffitto” is an Italian word, 
and means “scratched.” Scratched decoration is the 
most ancient mode of surface decoration employed by 
man. The primitive savage of the flint-weapon period 
used this simple form of ornamentation. Scratched 
work, as used by prehistoric man, may be fitly termed 
the proem of the civilized arts of drawing, modelling and 
sculpture. The term is now employed for plaster deco¬ 
rations, scratched or incised upon plaster or cement be¬ 
fore it is set. It may be used for both external and 
internal decoration. The annexed illustrations (Nos. 25 
and 26) will demonstrate the high degree to which the 
art of sgraffitto attained in Italy. 

Some graffittos are really low relief work rather than 
the sgraffitto, they being very deep cut with the iron or 
steel point, which was necessitated by the final coat be¬ 
ing plastered on instead of washed on. Deep cutting 
243 


244 


CEMENTS AND CONCRETES 



Sgraffitto Frieze from Florence. 
NO. 26. 









































































































































MISCELLANEOUS MATTERS 


245 


gives a hard appearance to the design, prevents the water 
from running off the walls, and catches the dirt. In exe¬ 
cuting true sgraffitto, the cut or scratch should be ex¬ 
ceedingly slight—in fact, some parts scarcely percepti¬ 
ble. 

Sgraffitto decorations do not suffer materially from 
stubbing it with an old broom, leaving it barely half an 
inch from the finished face. For internal work, the ordi¬ 
nary pricking up suffices. When this is dry, a thin coat 
of selentic lime mixed with the desired coloring matter 
for the background, is floated over it. This background 
may be black, bone-black being used; red, for which use 
Venetian or Indian red, or the ordinary purole brown 
of commerce, singly or mixed, to produce any tone de¬ 
sired; yellow, produced by ochres or umbers; blue, by 
German blue, Antwerp blue, or any of the commoner 
blues, avoiding cobalt, and these colors you may use to 
any degree of intensity or paleness. When this coat is 
nearly dry, skim over it a very thin coat of pure selentic 
lime, which dries of a parchment color and generally 
suffices. If you want a pure white lime, use a moderate 
quick-setting one, as stiff as you can work it, and as 
each variety of lime has its own individual perversity, I 
can give no general direction, and would advise the be¬ 
ginner to stick to selentic, which is always procurable. 
You have, of course, prepared your cartoon. This is 
pricked and pounced as for any other transfer process, 
and then with an old, well-worn, big-bladed knife, for 
there is no better tool, you can cut round all the out¬ 
lines, and with a flat spatula clear away all the thin 
upper coat, leaving the colored ground as smooth as you 
can. If your plaster is not quite dry enough for the 
two coats to separate easily, wait a little longer, but not 
too long, for that is fatal. By the time you have cleared 


246 


CEMENTS AND CONCRETES 


out your background, the plaster will be in a good con¬ 
dition to allow you to cut out the finer parts of the de¬ 
sign, such as folds of the draperies, or the finer lines of 
the faces or of the ornament. Use your knife slightly 
on the slope, and if you want to produce half-tones, slope 
it very much; but, as a rule, the more you avoid half¬ 
tones, and the simpler and purer your line, the more 
effective your work will be. Recollect, above all things, 
you are making a design and not a picture, and you 
must never hesitate, for to retouch is impossible. Some¬ 
times it may be desirable to gild the background, and 
you can then carve or impress it with any design you 
choose. It occasionally happens you want to give some 
semblance of pictorial character to your work when it is 
small in scale and near the eye, and then you can pro¬ 
ceed as though you were cutting a wood-block. 

By cutting out your ground color in places, and 
plastering it with that of another color, you may vary 
any portion of it you desire. You can also wash over 
certain parts of your upper coat with a water-color if 
you desire, combining fresco with the sgraffitto, both of 
which manners are often used; but, as a rule, the broader 
your design, and the simpler your treatment of it, the 
better. It will be seen that this process is very available 
for simple architectonic effects; and for churches, hos¬ 
pitals, and other places where large surfaces have to be 
covered, it is the least costly process that can be adopted. 
It has also the great advantage of being non-absorbent, 
and it can be washed down at any time. The artist is 
untrammelled by difficulties of execution, but he should 
bear in mind that the more carefully he draws his lines 
and the simpler he keeps his composition, the more 
charmed with the process he will be, and the better will 
be the effect of his work. 


MISCELLANEOUS MATTERS 247 

A well-known artist records his experience of sgraffitto 
as follows: 

“Rake and sweep out the mortar joints, then give the 
wall as much water as it will drink, or it will absorb 
the moisture from the coarse coat, as it will not set, but 
merely dry, in which case it will be worth little more 
than dry mud. Care should be taken that the cement 
and sand which compose the coarse coat should be prop¬ 
erly gauged, or there may be an unequal suction for the 
finishing coats. The surface of the coarse should be 
well roughened to give a good key, and it should stand 
some days to thoroughly set before laying the finishing 
coat. When sufficiently set, fix your cartoon in its des¬ 
tined position with nails; pounce through the pricked 
outline; remove the cartoon; replace the nails in the 
register holes; mark with chalk spaces for the different 
colors, as indicated by the pounce impression on the 
coarse coat; lay the several colors of the color coat ac¬ 
cording to the design as shown by the chalk outlines; 
take care that in doing so the register nails are not dis¬ 
placed ; roughen the face in order to make a good key for 
the final coat. When set, follow on with the final sur¬ 
face coat, only laying as much as can be cut and cleaned 
up in a day. When this is sufficiently steady, fix up the 
cartoon in its registered position; pounce through the 
pricked outline ; remove the cartoon, and cut out the de¬ 
sign in the surface coat before it sets; then if the regis¬ 
ter is correct, cut through to different colors, according 
to the design, and in the course of a few days the work 
should set as hard and as homogeneous as stone, and as 
damp-proof as the nature of things permit. 

‘ ‘ When cleaning up the ground of color which may be 
exposed, care should be taken to obtain a similar quan¬ 
tity of surface all through the work, so as to get a broad 


248 


CEMENTS AND CONCRETES 


effect of deliberate and calculated contrast between the 
trowelled surface of the final coat and the scraped sur¬ 
face of the simple contrasts of light against dark, or 
dark against light. The following are the proportions 
of the various coats: 

‘ ‘ Coarse coats: One of Portland cement to 3 of washed 
sharp coarse sand. 

“Color coat: One and one-half of air-slaked Port¬ 
land to 1 of color laid % inch thick. Distemper colors 
are Indian red, Turkey red, ochre, umber, lime blue; 
lime blue and ochre for green; oxide of manganese for 
black. In using lime blue, its Violet hue may be over¬ 
come by adding a little ochre. It should be noted that 
it sets much quicker and harder than the other colors 
named. 

“Final coat, internal work: Parian, air-slaked for 
twenty-four hours to retard its setting, or fine lime and 
selenitic sifted through a fine sieve. 

“For external work: Three selenitic and 2 silver 
sand. 

“When finishing, space out the wall according to the 
scheme of decoration, and decide where to begin, and 
give the wall in such place as much water as it will 
drink; then lay the color coat, and leave sufficient key 
for the final coat. Calculate how much surface of color 
coat it may be advisable to get on to the wall, as it is bet¬ 
ter to maintain throughout the work the same duration 
of time between the laying of the color coat and the fol¬ 
lowing on with the final surface coat; for this reason, 
that if the color sets hard before laying the final coat, it 
is impossible to get up the color to its full strength wher¬ 
ever it may be revealed in the scratching of the decora¬ 
tion. When the color coat is quite firm, and all shine 
has passed away from its surface, follow on with the 


MISCELLANEOUS MATTERS 


249 


final coat, but only lay as much as can be finished in one 
day. The final coat is trowelled up, and the design 
is incised or scratched out. Individual taste and experi¬ 
ence must decide as to thickness of final coat, but if laid 
between % inch and 1-12 inch, and the lines cut with 
slanting edges, a side light gives emphasis to the fin¬ 
ished result, making the outlines tell alternately as they 
take the light or cast a shadow.” 

Another method which I have used in sgraffitto for 
external decoration was done entirely with Portland 
cement. This material for strap-work or broad foliage, 
or where minuteness of detail is unnecessary, will be 
found suitable for many places and positions. Three 
colors may be used if required, such as black for the 
background, red for the middle coat, and grey or white 
for the final coat. These colors may be varied and sub¬ 
stituted for each other as desired, or as the design dic¬ 
tates. The Portland cement for floating can be made 
black by using black smithy ashes as an aggregate, and 
by gauging with black manganese if for a thin coat. The 
red is obtained by adding from 5 to 10 per cent, of red 
oxide, the white by gauging the cement with white mar¬ 
ble dust, or with whiting or lime, the grey being the nat¬ 
ural color of the cement. After the first coat is laid, 
it is keyed with a coarse broom. The second coat is laid 
fair and left moderately rough with a hand-float. The 
suction of the first coat will give sufficient firmness to 
allow the third coat to be laid on without disturbing the 
second. The third coat should be laid before the sec¬ 
ond is set hard. The second and third coats may be 
used neat, or gauged with fine sifted aggregate as re¬ 
quired. The finer the stuff, the easier and cleaner the 
work, and the cut lines are more accurate and free from 
jagged edges. The outlines of the design • may be 


250 


CEMENTS AND CONCRETES 


pounced or otherwise transferred to the surface of the 
work, and the details put in by hand. The thickness of 
the second coat should be about 3-16 inch, and the third 
coat about % inch. The thickness of one or both coats 
may be varied to suit the design. The beauty of effect 
of this method of linear decoration, aided by two or 
three colors, depends greatly on the treatment of design, 
the clearness of the incised lines, and the pleasing color 
contrasts. It will be seen that in the three methods 
described there is a similarity, yet the method of using 
two color coats on a dark floating coat will give more 
variety and effect. There is a large use for sgraffitto in 
the future, as it has been in the past, and its use is inti¬ 
mately bound up with the future of cement concrete. 

In order that the foregoing examples of high-class 
sgraffitto may not deter the young plasterer from trying 
his “ ’prentice han’ ” in this class of work, some simple 
designs are given in the annexed illustration (No. 27). 
Fig. 1 shows a design for a frieze in two colors. The 
ground may be black or red, and the ornament buff or 
grey. The colored material for the ornament is laid 
first, and the colored material for the ground laid last. 
Fig. 2 shows a design for a cove in two colors, one with 
two shades. The ground is grey, and the band work 
buff. A deeper shade of buff for the honeysuckle can be 
obtained by brushing this part with liquid color made 
deeper than the original gauge, also by laying a black 
coat first, and in a line with the honeysuckle; then laying 
the buff stuff for the band work next, and then laying 
the grey color last. In the latter case the honeysuckle 
is cut deeper than the band work, so as to expose the 
black coat. 

Different effects can be obtained by changing the col- 


MISCELLANEOUS MATTERS 251 

ors. Sections of the surface of the frieze and part of the 
moulding are shown at the ends. 

Fresco .—The plasterer is closely allied to the artist 
painter. He has always to be in readiness to plaster the 
wall for the artist. Owing to the alliance with distin¬ 
guished artists, and the various methods of preparing 
and using the plaster materials, I am induced to give a 
few notes, also extracts from writers of authority. 



-Sgrafutto Frieze in Two Colours. 
NO. 27. 


Fresco is a mode of painting with water-colors on freshly 
laid plaster while it remains naturally wet. It is called 
“fresco” either because it was originally used on build¬ 
ings in the open air, or because it was done on fresh 
plaster. Fresco is an ancient art, being mentioned by 



















252 CEMENTS AND CONCRETES 

Pliny. Mr. Flinders Petrie found some remarkably fine 
specimens on floors and walls at Tel-el-Amarna, which 
reveal the state of the art four thousand years ago. Fine 
frescoes were discovered in the ruins of Pompeii. In 
one of the principal houses the plaster walls are adorned 
with theatrical scenes; in an inner room is the niche 
often to be seen in Pompeiian houses. The frescoes on 
the wall consist of floral dados. Above this is a whole 
aquarium, with shells, plants, birds and animals. They 
are all executed in their natural colors, and are natur¬ 
ally and gracefully drawn. Michael Angelo’s beautiful 
fresco on the ceiling of the Sistine Chapel in the Vatican 
is grand both in conception and execution. It measures 
133 feet in length by 43 feet in width. Raphael’s fres¬ 
coes in the Vatican, Farnesina Palace, &c., are wonder¬ 
fully fine, and may be regarded as the high-water mark 
of Cinque Cento decoration. 

For fresco or buon fresco the lime has to be care¬ 
fully run, and the sand should be white, clean, and of 
even grain, being well washed and sifted to free it from 
impurities or saline properties. Silver sand is pre¬ 
ferred by some artists. The older the putty lime, the 
better the results. The lime is slaked in a tub, and then 
run through a fine wire sieve into a tank, and after being 
covered up, is left for three months. It is then put into 
the tub again, and re-slaked, or rather well worked, and 
run through a fine hair sieve into earthenware jars or 
slate tanks, and the water which collects at the top drawn 
or poured off, the jars or tank being covered over to ex¬ 
clude the air. Lime putty in this state will keep for an 
indefinite time without injury. From 2 to 4 parts of 
sand to 1 part putty is usual. Marble dust alone is 
sometimes used in place of sand, and also sand with 
equal parts. Every difference of lime and sa,nd found 


MISCELLANEOUS MATTERS 


253 


in various localities should be considered and tested be¬ 
fore using. A soft sand is quickly dissolved by a 
strong lime, and a plaster made of this is fit for use 
sooner, and will deteriorate more quickly than a plaster 
made with a less powerful lime and a harder sand, or 
with marble dust. 

The wall surface to be plastered must be well scraped 
and hacked, the joints raked out and brushed, and the 
whole surface well scrubbed and wetted. The rendering 
is done with the best possible prepared old coarse stuff. 
If the walls are rough or uneven, they should be first 
pricked up and then floated. In any case, the surface 
is left true, and with a rough face, to receive the fin¬ 
ishing coat. Portland cement or hydraulic lime gauged 
with sand, also gauged with coarse stuff, has been used 
where the walls were damp (damp is fatal to fresco), 
or if exposed to the atmosphere. When Portland cement 
or hydraulic lime is used, the work should be allowed to 
stand until thoroughly dry to allow any contained sol¬ 
uble saline efflorescence to come to the surface. This is 
brushed off with a dry brush, and a few days are allowed 
to elapse to see if there is a further efflorescence. When 
this is all extracted and swept off, and the artist is ready 
to commence, the wall is washed with a thin solution of 
the fine setting stuff, and then laid about y 8 inch thick, 
with well-beaten, worked, and tempered fine setting 
stuff. It is then rubbed with a straight-edge and scoured 
with a hand-float (using lime water for scouring) until 
the surface is true and of uniform grain. Most artists 
prefer a scoured surface without being trowelled. No 
more surface should be covered than can be conven¬ 
iently painted in one day. While the plaster is still 
soft and damp, the cartoon is laid on, and the lines and 
details pounced in or indented by means of a bone or 


254 


CEMENTS AND CONCRETES 


hard-wood tool. Should the finishing coat get too dry 
in any part, it can be made fit for work by using a fine 
spray of water. The method of plastering and the gaug¬ 
ing of materials may slightly vary according to the de¬ 
sire of the painter and the kind of fresco in hand. The 
following is taken from an old manuscript dated 1699:— 

“1. In painting the wall to make it endure the 
weather, you must grind colors with lime water, milk, or 
whey, mixed in size. 

“2. Then paste or plaster must be made or well- 
washed lime, mixed with powder of old rubbish stones. 
The lime must be often washed till finally all the salt is 
extracted, and all your work must be done in clear and 
dry weather. 

“3. To make the work endure, stick into the wall 
stumps of headed nails, about 5 or 6 inches asunder, and 
by this means you may preserve the plaster from peeling. 

“4. Then with the paste plaster the walls a pretty 
thickness, letting it dry; but scratch the first coat with 
the point of your trowel longways and crossways, as 
soon as you have done laying on what plaster or paste 
you think fit, that the next plastering you lay upon it 
may take good key, and not come off nor part from the 
first coat of plastering; and when the first coat is dry, 
plaster it over again with the thickness of half a barley¬ 
corn, very fine and smooth. Then, your colors being al¬ 
ready prepared, work this last plastering over with the 
said colors in what draught or design you please—his¬ 
tory, etc.,t—so will your painting unite and join fast to 
the plaster, and dry together as a perfect compost. 

“Note—Your first coat of plaster or paste must be 
very haired with ox-hair in it, or else your work will 
crack quite through the second coat of plastering; and 
will spoil all your painting that you paint upon the sec- 


MISCELLANEOUS MATTERS 


255 


ond coat of plastering; but in the second coat that is 
laid on of paste or plaster there must be no hair in it at 
all, but made, thus:— 

Mix or temper up with well-washed lime, fine powder 
of old stones (called finishing stuff) and sharp grit sand, 
as much as you shall have occasion for, to plaster over 
your first coat, and plaster it all very smooth and even, 
that no roughness, hills, nor dales, be seen, nor scratch of 
your trowel. The best way is to float the second coat of 
plastering thus:—After you have laid it all over the 
first coat with your trowel as even and smooth as pos¬ 
sible, you can then take a float made of wood, very 
smooth, and 1 foot long and 7 or 8 inches wide, with a 
handle on the upper side of it to put your hand into 
to float your work withal, and thus will make your 
plastering to lie even; and lastly, with your trowel you 
may make the said plastering as smooth as possible. 

“5. In painting be nimble and free; let your work 
be bold and strong; but be sure to be exact, for there is 
no alteration after the first painting, and therefore 
heighten your paint enough at first; you may deepen at 
pleasure. 

“6. All earthy colors are best, as the ochres, Spanish 
brown, terra-vert, and the like. Mineral colors are 
naught. 

“7. Lastly, let your pencil and brushes be long and 
soft, otherwise your work will not be smooth; let your 
colors be full, and flow freely from the pencil or brush; 
and let your design be perfect at first, for in this there 
is no alteration to be made.” 

Fresco Secco .—Closely allied with the genuine fresco 
(fresco buono) is another kind called fresco secco (dry), 
or mezzo (half) fresco. The plaster work for fresco sec¬ 
co is similar to that used for fresco buono. It is allowed 


256 


CEMENTS AND CONCRETES 


to stand until thoroughly dry. The surface is then 
rubbed with pumice-stone, and about twelve hours before 
the painting is commenced it is thoroughly wetted with 
water mixed with a little lime. The surface is again 
moistened the next morning, and the painting begun in 
the usual way. If the wall should become too dry, it is 
moistened with the aid of a syringe. There is no fear of 
joinings in the painting being observable, and the artist 
can quit or resume his work at pleasure. Joinings are 
distinctly noticeable in the frescos in the Loggia of the 
Vatican. Fresco secco paintings are heavy and opaque, 
whereas real fresco is light and transparent. While the 
superiority of fresco buono over fresco secco for the 
highest class of decorative painting is unquestionable, 
still the latter is suitable for many places and forms of 
decorative paintings. The head by Giotto in the National 
Gallery, from the Brancacci Chapel of the Carmine at 
Florence, is in fresco secco. 

Indian Fresco and Marble Plaster .—“Fresco painting 
is a common mode of decoration in Jeypore, and is used 
in ornamenting walls inside and outside of buildings— 
also as a dado or border round the wainscot or on the 
floor—and on any surface where decoration is desired. 
The beautiful marble plaster on which it is done is com¬ 
mon Rajputana, and is used to line the surface of walls 
or floors, and of baths or bath-rooms. It is admirably 
adapted to places where coolness and cleanliness are de¬ 
sired, and is very suitable to a warm climate. It would 
no doubt be more commonly used if pure lime could be 
obtained. 

“To prepare the marble plaster, the process in use in 
Jeypore is as follows:—Take pure stone lime, mix 
it with water until it has dissolved, then strain it through 
a fine cloth. In Jeypore the lime is made from pounded 


MISCELLANEOUS MATTERS 


257 


marble chips or almost pure limestone. The substance 
which remains in the cloth is called bujra, and all that 
passes through the cloth is called ghole. These should 
be prepared a few days before they are required so as 
to allow time to settle, and every day the water should 
be changed, so as to leave a very fine sediment. 

“Jinki, which is also used, is pure marble ground to 
a very fine powder; kurra is a mixture of bujra and 
jinki; and jinkera is a mixture of ghole and kurra. 
These are the materials used, and the names by which 
they are known in Jeypore. In Madras, where similar 
plaster is used, it is made, I believe, from shells and the 
ingredients are probably known by other local names. 

“If the surface to be polished is a slab or stone, the 
kurra mixture consists of 1 part by weight of burja and 
iy 2 parts of jinki. If the surface is a wall or a chunam 
floor, it must be first thoroughly dry and consolidated— 
then take equal parts of burja and jinki to form the 
kurra mixture. Mix the burja and the jinki well to¬ 
gether; add a little water and grind them well together, 
in the same ways as natives mix their condiments, by 
hand with a stone rolling-pin on a slab, until they form 
a perfectly fine paste. Wet the surface which is to be 
polished, and spread over it a layer of this kurra mix¬ 
ture, about Ys inch thick. Then beat the surface gently 
with a flat wooden beater, sprinkling a few drops of 
clean water on the surface occasionally. Then mix a 
little ghole with the kurra plaster (described above as 
jinkera) and lay it on evenly with a brush as if it were 
a coat of paint; rub the surface over carefully with any 
close-grained flat stone, called in Jeypore jhaon. The ob¬ 
ject of this is to smooth down all irregularity and 
roughness, and to prepare a smooth even surface. 
Sprinkle a few drops of water and repeat the process, 


258 


CEMENTS AND CONCRETES 


taking care that no hollow places are allowed to re¬ 
main. Paint it over with fine jinkera (ghole and 
kurra mixed), increasing the proportion of ghole, and 
rub it down well with a flat stone (jhaon) as before; 
then paint it over with ghole only, after each coat rub¬ 
bing it down carefully with the jhaon stone. After this, 
rub it all over with a soft linen cloth, called in Jeypore 
nainsukh, folded into a pad. Then give it another coat 
of ghole, and now rub it down carefully with a piece of 
polished agate, called in Jeypore ghinti, until it begins 
to shine. The surface must not be allowed to dry too 
rapidly, or a good polish will not be obtained. Care 
must be taken that the lime has been thoroughly slaked 
in the first instance, or it may blister; also that the sur¬ 
face, if a floor, is thoroughly consolidated, as the least 
settlement naturally causes the plaster to crack. The 
polishing process with the" agate cannot be repeated too 
often; the more it is carefully done, the better will be 
the polish. Every time the agate is moved backwards 
it should be made to pass over a portion of its previous 
course, so as to prevent any mark or line at the edge. 
Lastly, if the surface is to remain white, take some water 
which has been mixed with grated cocoanut, and lay it 
on the surface. Let it dry, and then rub it down with a 
fine cloth folded into a pad. If any coloring is desired, 
the same process is adopted until the polishing with the 
agate is begun. This is only done slightly. If any pat¬ 
tern is desired, it is drawn on paper and pricked out. 
The paper is placed on the surface, and is dusted with 
very finely powdered charcoal tied up in a muslin bag. 
The charcoal passes through the perforations and marks 
the plaster surface. The paints are mixed with water, 
and are painted on by hand while the surface is still 
fresh and moist hence the term fresco. Where a large 


MISCELLANEOUS MATTERS 


259 


surface has to be done, it is necessary to employ several 
men at the same time, in order that the surface might 
be all painted before it has time to dry; or else the pat¬ 
tern must be so arranged that the connection of one 
day’s work with the work of the next will not be amiss. 
Immediately after the surface has been painted the 
colors are beaten in with the back of a small trowel, in 
such a manner that the color is not rubbed or mixed 
with the color adjacent. As soon as it shows to the 
touch that the color has become incorporated with the 
plaster, the surface is painted over with water mixed 
with grated cocoanut, and is then polished down with 
the agate. 

“The following colors can be used in process:—Lamp 
black; red lead; green (from a stone known as hara 
pathar); yellow (from a stone called pila pathar); 
brown or chocolate. A little glue is mixed with the two 
first colors, and gum only with the others. The colors 
used are mostly earths or minerals, as other will not 
stand the action of the lime. Vegetable pigments can¬ 
not be used for this model of painting, even when mixed 
with mineral pigments, and of the latter only these are 
available which resist the chemical action of the lime. 
The lime in drying throws out a kind of crystal surface 
which protects the color and imparts a degree of clear¬ 
ness superior to that of any work in tempera or size 
paint. The process, although apparently simple, re¬ 
quires dexterity and certainty of hand, for the surface 
of the plaster is delicate, and the lime only imbibes a 
certain quantity of additional moisture in the form of 
liquid colors, after which it loses its crystallizing quality, 
and the surface or a portion of it becomes rotten. It is 
only after the lime has dried that such flaws are dis¬ 
covered, and the only remedy is to cut away the de- 


260 


CEMENTS AND CONCRETES 


fective portion, lay on fresh plaster and do the work 
over again. The colors become lighter after the plaster 
dries, so allowance mnst be made for this. The advan¬ 
tages which this process possesses are clearness, ■ exhib¬ 
iting the colors in a pure and bright state; the surface 
is not dull and dry as in tempera or size painting, nor 
glossy as in oil painting; it can be easily seen from any 
point, and it is not injured by exposure to the air; it 
will stand washing, and can be cleansed with water with¬ 
out injury.” 


Scagliola. 

Historical .—Scagliola derives its name from the use 
of a great number of small pieces or splinters ; scagliole 
of marble being used in the best description of this 
work. It is said to have been invented in the early part 
of the sixteenth century by Guido Sassi, of Cari, in 
Lombardy, but it is more probable that he revived an 
old process, and introduced a greater variety of colors 
in the small pieces of marble and alabaster used to 
harden the surface, and better imitate real and rare 
marbles. It is sometimes called misckia from the many 
mixtures of colors introduced by it. The use of colored 
plaster for imitating marbles was known to the ancients, 
although the pure white, or marmoratum opus and al - 
barum opus, mentioned by Pliny, was more used. The 
plastic materials used by the Egyptians in coating the 
walls of their tombs partook of the nature of marble. 
The ancients also used a marble-like plaster for lining the 
bottoms and sides of their aqueducts, which has endured 
for many centuries without spoiling or cracking. In the 
decoration of their domes the Moors used colored 
plasters, which have stood the ravages of time. The 


MISCELLANEOUS MATTERS 


261 


beautiful chunam or plaster of India, as used by the 
natives, has a hard surface, takes a brilliant polish rival¬ 
ling that of real marble, and has withstood for many 
ages the sun and weather without sign of decay. The 
roofs and floors of many houses in Venice are coated with 
smooth and polished plaster, made at a later date, strong 
enough to resist the effects of wear and weather, 
without visible signs of crack or flaw, and without much 
injury from the foot. Scagliola was largely employed 
by the Florentines in some of their most elaborate works. 
It has been used in France with great success for archi¬ 
tectural embellishment. The rooms are so finished that 
no additional work in the shape of house-painting is 
required, the polish of the plaster and its evenness of 
tint rivalling porcelain. Scagliola is the material used. 
At times the surface of the plaster is fluted, or various 
designs are executed in intaglio upon it in the most 
beautiful manner. 

Scagliola is one of the most beautiful parts of decora¬ 
tive plaster work, and it is regrettable that there should 
not be a greater revival of such a charming and beautiful 
art. Its limited use in recent times is greatly owing to 
its manufacture being restricted by rules and rigid 
methods and even prejudices, and being confined to 
monopolists, who kept the method secret until it was 
looked upon as a mystery which greatly enhanced its 
cost. But through the information now at hand, com¬ 
bined with a little practical experience and enterprise, 
there is no valid reason why architects should not adopt 
it for second or even for third class buildings. It 
possesses great beauty, and is capable of affording grand 
effects and the richest embellishments in architecture. 
Scagliola, in skilful hands, can be produced in every 
variety of color and shade, in every possible pattern, in 


262 


CEMENTS AND CONCRETES 


every conceivable form and size, from a paper weight 
to the superficial area of a large wall. It can be made 
at a price that would enable it to take the place of the 
most durable material now in use. Experience has 
proved that it will last as long as the house it adorns, 
and with an occasional cleaning, it will always retain its 
polish and beauty. It has been produced in past days 
in our own and other lands, and carried to such high ex¬ 
cellence, that many of the precious marbles, such as 
jasper, verd antique, porphyry, brocatello, giailo an¬ 
tique, Sienna, etc., have been imitated so minutely, and 
with an astonishing degree of perfection, as to defy de¬ 
tection. It will not only retain its polish for years, but 
can be renovated at much less comparative cost than 
painting and varnishing marbled wood, or plaster work. 
It is cheaper and more satisfactory to use scagliola in 
the first instance than to go to the expense of plastering 
walls, columns, etc., with Keen’s or other kindred ce¬ 
ments, used for their hardness and ready reception of 
paint, which are to be afterwards marbled and var¬ 
nished. Both are imitations, but painted marble can 
never be compared with scagliola, which has the look, 
color, touch, and polish of the more costly natural 
marbles. 

Various Artificial Marbles .—Various patents have 
been taken out for the production of artificial marbles, 
having for their bases plaster of Paris. These patents 
will be briefly mentioned here. 

Evaux’s Artificial Marble is composed of plaster mixed 
with albumen and mineral colors, the ground being zinc 
white. Rowbotham also employed plaster and albumen 
soaked in a solution of tannic acid. Lilienthal makes 
an artificial marble with Keen’s cement, slaked lime, and 
curdled milk. 


MISCELLANEOUS MATTERS 263 

Tick s ‘ Neoplaster. ’ ’—This composition was patented 
in 1883, and is composed of 75 per cent, of plaster, mixed 
with feldspar, marl, coke dust, and pumice-stone. Gule- 
ton and Sandeman patented an artificial marble in 1876. 
It is composed of Keen’s cement backed with fibre, and 
soaked or brushed on the back with a solution of as¬ 
phalt. The slabs were made in glass moulds. La- 
roque’s patent marble, is formed of plaster and alum 
gauged with gum water, the veining being done with 
threads of silk dipped in the required colors. The 
backs of the slabs or panels are strengthened with can¬ 
vas. 

Mur Marble is composed of a mixture of Keen’s and 
Marin’s cement in equal proportions, made into a paste, 
with a solution of sulphate of iron and a small quanti¬ 
ty of nitric acid in water. The slabs are dried and 
tarred at a temperature of 250 degrees F. for about 
twenty hours, and when cool are rubbed, colored, var¬ 
nished, or japanned, as required. There is another 
patent formed of plaster, gauged with a solution con¬ 
taining tungstate of soda, tartaric acid, bicarbonate of 
Soda, and tartarate of potash. Another is composed of 
Keen’s cement 10 parts, ground glass 1 part, and alum 
V 2 part, dissolved in hot water. 

Guattaris Marble is obtained by transforming gypsum 
(sulphate of lime) into carbonate of lime (marble). 
There are two methods. The first consists of dehy¬ 
drating blocks of gypsum, and then hardening by im¬ 
mersion in baths containing solutions of silicate of soda, 
silicate of lime, chloride of lime, sulphate of potash, 
soda, acid phosphate of lime, etc. The blocks are cut 
into slabs or carved before being put into the bath. The 
second method consists in dehydrating the gypsum, and 
bathing in some of the above chemicals. They are then 


264 


CEMENTS AND CONCRETES 


dried and burnt at a red heat, and allowed to cool. 
After a second burning and cooling, the products are 
ground as for plaster. This powder is called “Marmo- 
rite”. The marmorite is gauged in a trough with some of 
the water from the baths as above, kneaded into a paste, 
and the colors added and mixed. The paste is then put in¬ 
to moulds and pressed, and when set they are taken out, 
dried, and finally polished. Mineral colors are used. 
Yellow and its tints are obtained with citrate of iron 
dissolved in oxysulphate of iron, sulphate of cadmium, 
chloride of yttrium, chromate of lithium, and yellow of 
antimony. Red and its tints are obtained with dragon’s 
blood, sesquioxide of iron, mussaride red, and sulphate 
of didymium, and the salts derived from it, which give 
a rose color. Azure blue is obtained with sulphate of 
sodium mixed with acetate of copper and tartaric acid 
and oxide of cobalt. Green and its tints are obtained 
with verdigris, hydrochlorate of cobalt. Black is ob¬ 
tained by pyrolignite of iron reduced by boiling in gallic 
acid with sirco black. Black marble is also obtained 
by immersing gypsum blocks or slabs or the cast mar¬ 
morite in a hot preparation of bitumen. During this 
operation the dehydration of the material under treat¬ 
ment is accomplished, and the bitumen not only pene¬ 
trates the mass, but fills up all the pores and spaces 
evacuated by the water which was contained in the ma¬ 
terial treated, and a hard mass of brilliant black is ob¬ 
tained in every way equal to Flanders marble. It is 
said that the above imitation marbles are largely used in 
Florence. 

Scagliola Manufacture .—Scagliola can be made in situ 
or in the work shop, according to the requirements of the 
work; but in either case it is necessary that the work 
place should be kept at a warm temperature, and the 


MISCELLANEOUS MATTERS 


265 


work protected from dust or damp atmosphere. The 
plaster should be the strongest and finest in quality, and 
free from saline impurities. It should be well sifted to 
free it from lumps or coarse grains, which otherwise 
would appear as small specks of white in the midst of 
the dark colors when the polishing is completed. Glue 
water should be made in small quantities, or as much as 
will suffice for the day, as it deteriorates if kept too long. 
Glue tends to harden the plaster, and gives gloss to the 
surface. Unfortunately it is also the cause of its sub¬ 
sequent dullness and decay when exposed to moisture 
and damp air, hence the necessity of using the best glue, 
good and fresh glue water. If scagliola is required to be 
done in situ on brick walls, the joints should be well 
raked out and the walls well wetted. This gives a good 
key, stops the excessive absorption, and partly prevents 
the evil effects of saline matters, that are found in most 
kinds of new bricks. These saline matters are the prin¬ 
cipal cause of subsequent efflorescence which sometimes 
appears on plastic surfaces, and is so unsightly and dis¬ 
astrous to surface decorations. Saline matters are also 
caused by acids, used in the manufacture of some ce¬ 
ments. Saline is also found in mortars made with sea 
water, or with unwashed sea sand. These impurities 
can be avoided by carefully selecting, mixing, and work¬ 
ing of the materials. Brick walls for scagliola should 
be allowed to stand as long as possible, and wetted at in¬ 
tervals. This allows more time for the saline to exude 
and be washed off. The exudation may be hastened or 
the salts absorbed and killed by brushing the walls with 
a solution of freshly slaked lime. This is allowed to stand 
until dry, and then cleaned off by scrubbing with warm 
water and a coarse broom. If space permits, a wall bat¬ 
tened and lathed is the best preventive. Scagliola slabs, 


266 


CEMENTS AND CONCRETES 


screwed to plugs or battens, are protected from saline 
and internal damp. 

Iron columns to support overhead weights, and fixed 
as the building proceeds, are often covered with scaglio- 
la. If the work is done in situ, the iron core is sur¬ 
rounded with a wood skeleton and strong laths, or paint¬ 
ed wire lathing. The wood templates are cut, equal to 
the lower and upper diameters of the columns, and one 
fixed at the top and bottom of the shaft. The ground 
work is then ruled fair with a diminished floating rule. 
This gives a guide and equal thickness for the scag (the 
trade abbreviation for scagiiola stuff). 

The floating coat is composed of the best and strong¬ 
est plaster procurable, and gauged as stiff as possible 
with sufficient strong size water, so that it will take from 
twelve to twenty-four hours to set. The floating is gen¬ 
erally brought out from the lath in one coat. A tenth 
part of well-washed hair is sometimes mixed with the 
gauged plaster, to give greater toughness and tenacity. 
The surface must be carefully scratched with a singly- 
pointed lath, to give a sound and regular key for the 
scag, which is laid on in slices, and pressed and beaten 
with a stiffish, square pointed gauging trowel, somewhat 
like a margin trowel. The scag is laid about % inch 
fuller than the outline, and when set, the surface is 
worked down with a “toothed plane.” This plane is 
similar to that used by cabinetmakers for veneering pur¬ 
poses. The irons are toothed in various,degrees of fine¬ 
ness, and set at an angle of 70 degrees. If the columns 
are fluted, a half-pound plane is required for the flutes. 
As the planing proceeds, the outline is tested at inter¬ 
vals with a rule, as a mason does in using a straight¬ 
edge when working mouldings. A planed or chisel-cut 
surface shows up the grain and figure of the marble 


MISCELLANEOUS MATTERS 


267 


much better than if ruled. A rule is apt to work out or 
otherwise spoil the figure of most marbles. The t eating 
on the slices may disturb the figure of the marble at the 
outer surface, but if the seag is gauged stiff, the inner 
portion will be intact, hence the advantage of planing. 
To obtain greater cohesion between the scag and the 
floating, the latter is brushed with soft gauged stuff just 
before each piece of the former is laid. The scratching 
is also filled up at the same time, so as to obtain the full 
power of the key with the least amount of pressing on 
and beating the scag slices in position. When the shaft 
is planed, the wood colors are taken off; then the base 
and necking moulding, which has been previously cast, 
are screwed in position, using plaster (colored the same 
as the ground of the marble) for the joints. When dry, 
the whole is stoned and polished. Pilasters or other 
surface work done in situ are executed by similar pro¬ 
cesses. Cast and turned work should always he support¬ 
ed by strong woe den frames, formed with ribs, and cov¬ 
ered with % inch to % inch thick sawn laths. The 
strength of the frames is regulated according to the posi¬ 
tion and purpose of the intended work. For example, a 
column with base placed on a square pedestal would not 
require so strong framing as the pedestal which has to 
support the column and base. Also being on the floor 
level, it is more exposed to contact and pressure. Fram¬ 
ing is also necessary for fixing purposes, and to allow 
for the work being handled freely when being moved 
from the work shop to the building, and when being 
fixed. Small work may be made without framing. 
Turned columns are framed in two different methods, 
each way being for a special purpose. If it is an “in¬ 
dependent column ”, or in other words a complete col¬ 
umn, not intended to surround a brick or iron core, the 


268 


CEMENTS AND CONCRETES 


frame is made lighter and thinner, and in such ways as 
to admit the column to be cut either in two equal parts, 
or with one-third out, or just as much as will allow the 
larger part to pass over the iron core. Care must be 
taken that the inner diameter of the skeleton frame is 
greater than the diameter of the iron core. This is to 
allow' for fixing. The outer diameter of the frame is made 
about 1 inch less than the finished outline of column, to 
allow % inch for the core and % inch for the scag. The 
two parts of the frame are fixed with wooden pegs (not 
nails), so that they may be sawn when the column is cut 
into halves. This is not done until the column is pol¬ 
ished and ready for fixing. The parts are best separated 
by cutting with a thin and fine-toothed saw. The thin¬ 
ner the cut the better the joint. The two parts are 
fixed on the iron core with brass screws or clamps, from 
3 to 4 feet apart, and the joints made good with colored 
plaster as before. Sometimes a zigzag joint is made, the 
one side fitting the other, to give the marble or figure a 
more regular and natural appearance. The joints are 
then stopped with various tints, these being the same 
gauge as used for the face. 

Sometimes the framing is made longer than the shaft, 
so as to project at each end. These projecting parts are 
used as fixing points for screws, and binding round with 
hoop-iron before the plinth and cap are fixed. These 
parts project the edges of the work while being moved 
and fixed. Considerable skill and patience is required 
to make a strong joint, well polished, and imperceptible 
to the eye. The frames are made with solid ends, with 
a square hole in each to fit the spindle. The solid ends 
are cut out of inch deal, and are used to keep the skele¬ 
ton firm and in a central position when the spindle is 
turning on its bearings. One of the ends is fixed to 


MISCELLANEOUS MATTERS 


269 


flange of the spindle with screws. If a case column is 
being made, the solid ends are taken off before the col¬ 
umn is cut; but they form permanent parts of the fram¬ 
ing for an independent column. The mould is fixed at 
one side, and level with the centre of the spindle, which 
is the centre of the column’s diameter. Care must be 
taken that the profile of the mould plate to the centre 
of the spindle is one-half of the required diameter at 
each end of the shaft. 

Vases are generally made without wood framing. They 
are turned on a spindle with a plaster core screwed to the 
flange in the form of a parabola, to give the form of the 
hollow inside. On the core a coat of scag is laid and al¬ 
lowed to set. This is scratched to give a key for the 
coarse plaster which forms the body of the vase. This 
is formed to the desired outer profile by means of a 
mould fixed on the outside, and muffled to allow for a 
thickness of outside scag. When the core is run, the 
muffle is taken off, and the scag laid, keeping it about y 8 
inch thicker than the true profile, to allow for turning 
and stoning. When the scag is set, it is turned, and 
then the vase is taken off the spindle and plaster core. 
The spindle hole is used as a key for a slate or iron dowel 
for fixing the vase on to the square plinth. The vase is 
then polished. Cheap work is usually run or turned 
with a mould. This is done to save turning with chisels, 
but it spoils the true figure of most marbles. 

A more recent way of imitating marbles is known by 
the name of Marezzo, which does not require so much 
polishing, being made on plate glass or other smooth 
surface. Keen’s superfine plaster is used. The mode 
of making Marezzo is described later on. Specimens of 
the real marbles, to give the color and form of veining, 


270 CEMENTS AND CONCRETES 

spots, and figures, will be of great service to the be- 
ginner. 

Mixing .—Mixing the colors is an important part of 
scagliola manufacture, and the following colors, mixing 
and mode of using, will serve as an index for the imi¬ 
tating of any other marble that is not detailed. Fine 
plaster (not cement) is used for making the best class 
of scagliola, gauged with sized water/which is made by 
dissolving 1 lb. of best glue with 7 quarts of water. (This 
is known in the trade as “strong water”.) The stuff, 
when gauged will take about six hours to set. All mix¬ 
ing is done on a clean marble or slate slab. One of the 
principal arts is the mixing, but there are no two men 
who mix exactly alike, and it is largely a matter of ex¬ 
perience. The chopping or cutting into slices with a 
knife is another important point in the mixing, apart 
of course from the special colors. Where there are two 
shades of one color in any given work, the cutting does 
not affect their original shade. No dry color is used, 
only ground water-colors. The beginner had better ex¬ 
periment with a small sample of “Penzatti” or Pen¬ 
zance marble. With one gill of size water, gauge plaster 
middling stiff, then mix thoroughly with the gauged 
plaster a little red. Do the same with a little black. 
(See quantities below.) Blend this stuff properly by 
working it on the bench with the hands (not tools), then 
roll it out, and cut it into slices about one inch thick. 
Take up these slices, and part them with the fingers 
about the size of a walnut, and put them aside, a little 
distance apart, on a bench. 

The veining in this instance is white. Over these little 
lumps scatter half a handful of crumbs, made by re¬ 
serving a little of the gauged plaster, and making it 
crumbly with dry plaster, mixing with it a few small 


MISCELLANEOUS MATTERS 


271 


bits of alabaster or marble. Then gauge a little plaster 
in a basin, with a tooth brush, about 2 inches wide, dip 
into this gauged plaster, and smudge the little lumps all 
over with it. Knock these lumps together into a big one, 
and chop the big lump three times. (This chopping 
means cutting with a knife into slices once, and knock¬ 
ing up again; cutting with a knife a second time, and 
knocking up again; and then cutting with a knife a third 
time, when it is finished.) This lump is then ready to 
be cut into slices, and applied to any purpose required; 
but in this case, being wanted for a specimen, it is cut 
into slices about % inch thick, and laid close together 
.flat on a sheet of paper, and allowed to remain until set. 
It is then planed, and when dry polished. This opera¬ 
tion is an embodiment of the principle of “scag” mix¬ 
ing nearly from beginning to end, only submitting one 
color for another for the various marbles. The mixing 
is generally known as plain and i;ich, and may be 
described thus: Take a Sienna pedestal, for instance. 
Two shades of sienna, plain mixing; one or two shades 
of dark with veining, rich mixing, both done on the same 
principle as Penzatti. They are cut into slices and laid 
on alternately. All veining of any color is done as 
described above, only modified by the consideration that 
if strong veining is wanted the stuff must be stiffish, and 
for fine veining it must be slightly softer. Various-sized 
measures for the water and scales for weighing the color 
should be used. Pats of each gauge should be set aside 
as test pats to determine when the main portion of stuff 
is set. It is advisable to number the pats for future 
reference as to quantity of colors, time of setting, and 
tints when dry. The various colors and tints are gauged 
and chopped as previously described, and according to 
the marble required. The core being laid on the skele- 


272 


CEMENTS AND CONCRETES 


ton, and left in a keyed and rough state until dry and 
expansion ceased, it is ready when set for the scag. The 
core is now damped and well brushed with the white or 
other vein that has to be made. The veining is gauged 
thin, and being brushed and laid in the core, will tend to 
make the slices adhere better, and fill up the interstices 
caused by the jagged edges of the cut slices. The slices 
are then taken and pressed firmly onto the core, arrang¬ 
ing in proportion to the figure of the marble. To render 
the work more dense, beat it with a flat-faced mallet 
and a large gauging trowel with a square end. Try the 
work with a rule to see if the surface is fair. The 
rough surface should not be less than % inch thicker 
than the true line of the work, to allow for planing and 
stoning. When required, pieces of alabaster are inserted 
before the stuff is set. Metallic ores are used in 
some marbles, also pieces of granite and real 
marble. When the scag is laid, the work is left until 
set and dry. It is then planed stopped, stoned and 
polished. Columns and circular work are turned on a 
lathe, and the rough surface reduced to the true profile 
with long chisels similar to those for turning wood or 
other materials. This should not be attempted until the 
materials are thoroughly set. 

Colors and Quantities .—The following are the colors 
and quantities used for various marbles. The propor¬ 
tions of strong water, which is made varies, the due 
quantity should be tested by gauging small pats of 
plaster to ascertain the time of setting. As the tints of 
real marble vary in some species, the mixing must to 
some extent be left to the ingenuity of the workman. 
With a little practice and perseverance, a careful and 
observant man will soon succeed in getting the required 
tints. 


MISCELLANEOUS MATTERS 


273 


Penzance Marble .—10 oz. of light purple brown to 1 
pint. Yeining (plain mixing), 2 oz. black to 1 gill; vein- 
ing (rich mixing) 5 oz. black to y 2 pint; yeining (rich 
mixing), 1 oz. black to y 2 gill. All liquid measurements 
refer to strong water. 

Egyptian Green. —5 oz. black to 1 pint. Yeining, y 2 oz. 
green to y 2 pint light shade; yeining, y± oz. green to y 2 
gill. White the same, black chopped three times; a few 
black spots same as brown Beige. 

Brown Beige. —Four shades—1 light purple brown 
(indigo); 2 middle shades (blue black) ; 1 very dark 
shade (vegetable black). Yeining, burnt sienna with red 
alabaster spots—4 oz. (light shade) to y 2 pint; 4 oz. 
(middle) to y 2 pint; 4 oz. (very dark) to y 2 pint; 
y 2 oz. burnt sienna to % pint; % oz. black to % pint; 
y 2 pint for the grey with crumbs, and red alabaster 
spots. 

Dark Porphyry. —Color, light purple brown, with 
black, and a little ultramarine, blue spots, black, ver¬ 
milion grey, and a little red. 

Green Genoa. —2*4 oz. green to y 2 pint (rich mix¬ 
ing) ; 5 oz. black to 1 pint. Yeining, y 2 oz. green to y± 
pint. White veining the same, with alabaster spots, and 
black. 

Rouge Roy ale. —Color, light purple brown, with a little 
sienna, and umber, with ultramarine, blue or blue black. 
Yert-Yert.—% oz. green to y 2 pint; dark green with 
sienna; dry green plaster. 

Devonshire Red Marble. —All sienna work. Light 
mixing —1 shade grey; 1 shade lemon chrome; 1 shade 
light purple brown; 1 shade flesh color; veining burnt 
sienna. Dark mixing. i—1 shade light purple brown, 
with indigo blue in it; 1 shade dark purple brown; 1 
shade middling purple brown; 1 shade grey; 1 shade 


274 


CEMENTS AND CONCRETES 


lemon dirome. Veining, burnt sienna, with small ala¬ 
baster spots. 

Sienna Mixing. —5 oz. sienna to % pint, dark shade; 
3 oz. sienna to y> pint, middle shade; 2 oz. sienna to 
y 2 pint, light shade. 

Griotte Marble. —10 oz. of light purple brown to 1 
pint 5 oz. of dark purple brown to y 2 pint, with ala¬ 
baster spots. Ground with red veins, and small spots. 

Spanish Buff.— Burnt sienna, 2 shades, with large ala¬ 
baster spots. Veining, white and blue black, with small 
alabaster spots. Ground with red veins, and blue spots. 

Light Verd Antique. —2 y 2 oz. green to y 2 pint; 

1 y 2 oz. black to 1 gill; % gill black to 1 gill grey shade. 

Dark Verd Antique. —Green spots cut; grey spots cut; 
black spots with green and grey. Veining 2y 2 oz. green 
to % pint (rich mixing) ; 2% oz. dark green to % pint 
(rich mixing) ; % oz. black to % pint (rich mixing). 

Plain mixing, same as above, with small alabaster 
spots, and small black spots. 

Black and Gold. —5 oz. of black to 1 pint. Veining, 

2 shades dark sienna to y 2 pint (rich mixing) ; 2 shades 
light to y 2 pint (rich mixing); 2 parts light and grey, 
with alabaster spots, and crumbs. Veining must be stiff; 

3 oz. of black to 1 gill. 

Walnut.— 2 parts burnt umber; 1 part rose pink. 

Vert a Alps Marble. —5 oz. black to 1 pint. Veining, 
1% oz. of green to iy 2 gills; % oz. green to i/ 2 gill, with 
black crumbs chopped three times for the ground. 

Bosse De La Vantz Marble. —Rich mixing with indi¬ 
go blue—1 shade light purple brown; 1 shade dark pur¬ 
ple brown; 1 shade Venetian red. Veining, black for 
the ground, and white and green veining for the mixing, 
with alabaster spots and crumbs. 


MISCELLANEOUS MATTERS 


275 


Polishing White Scagliola .—White scagliola is often 
made with superfine Keen’s cement. A small portion of 
mineral green or ultramarine blue is added to improve 
and indurate the white color. White work requires spe¬ 
cial care to prevent discoloration or specks. When the 
work is left for drying purposes, or at the end of the day, 
it should be covered up with clean cotton cloths to pre¬ 
vent the ingress of dust, smoke or being touched with 
dirty hands. The tools should be bright and clean. Steel 
tools should be as sparingly used as possible. When the 
cement has thoroughly set and the work is hard, it is 
rubbed down with pumice-stone, or finely grained grit¬ 
stone, by the aid of a sponge and clean water, rubbing 
lightly and evenly until the surface is perfectly true. It 
is then stoned with snake-water (Water of Ayr), using 
the sponge freely and the water sparingly until all the 
scratches disappear. Afterwards well sponge the sur¬ 
face until free from glue and moisture. It is now ready 
for the first stopping. Stopping is an important part of 
the polishing process, and should be carefully and well 
done, to ensure a good, sound, and durable polish. 

First gauge a sufficient quantity of cement and clean 
water in a clean earthenware gauge-pot. The gauged 
stuff should be about the consistency of thick cream. It 
is well dubbed in, and brushed into and over the surface, 
taking care that no holes or blubs are left. When the 
stuff on the face gets a little stiff, scrape off the super¬ 
fluous stopping with a hard-wood scraper having a sharp 
edge. Then repeat the brushing (but not the dubbing) 
with the soft gauged stuff, and scraping two or three 
times, or until the surface is solid and sound. The work 
is now left until the cement is perfectly set. It is then 
stoned again for the third time with a piece of fine snake- 
stone, and stopped as before, with the exception that the 


276 


CEMENTS AND CONCRETES 


superfine stopping is not scraped off, but wiped off with 
soft clean rags. The work is left until the cement is set 
and the surface dry. It is then polished with putty 
powder (oxide of tin), which is rubbed over the surface 
with soft clean white rags, damped with clean water. In 
polishing mouldings, the stone must be cut or filed to fit 
each separate member of the moulding. 

Polishing Scagliola .—The polishing of scagliola is 
slightly different. It is rubbed down with a soft seconds 
(marble grit) or gritty stone, using the sponge and water 
freely until the surface is true. The glut and glue are 
cleaned off with a brush and sponge, using plenty of 
water, until the pores are free from grit. The moisture 
is sponged off, and the work left until sufficiently dry. 
It is then stopped in the same manner as white work, but 
using stiff stopping for large holes and steel scrapers in¬ 
stead of wood. The stopping is made with the same 
kind of plaster, size water, and color as was used for 
the ground color of the marble that is being imitated. 
The stopping and stoning is repeated as before, and it is 
finally polished with putty powder, using pure linseed oil 
instead of water. The repeated operations of stopping 
and stoning must not be proceeded with until the 
previous stopping is perfectly set, and the work dry. A 
small portion of spirits of turpentine is sometimes added 
to the gauged colored stuff to facilitate the drying. The 
work between each combined stopping and stoning will 
take from one to five days to dry, according to the size 
and thickness of the work and the state of the atmos¬ 
phere. Never dry the work by heat. The thorough dry¬ 
ness and hardness of the work are most essential be¬ 
fore proceeding to polish with the putty powder and lin¬ 
seed oil, because any contained damp will work out and 
spoil the polish. Work not perfectly dry may take a 


MISCELLANEOUS MATTERS 


277 


high polish, but it will soon go off when the damp comes 
through. Columns or large hollow work are not so liable 
to be affected by the damp, as it may escape through the 
back; but there must be some opening or ventilation to 
allow it to finally escape. 

If the polishing is well and carefully done, the polish 
produced on scagliola will equal, if not surpass, that on 
real marble. Tripoli polishing stone, sometimes called 
alana, is a kind of chalk of a yellowish-grey color. Water 
of Ayr stone is also used for polishing. In large work 
a rubber of felt dipped in putty powder may be used. 
Salad oil is sometimes used for finishing. Linseed oil 
makes the hardest finish, and dries quicker. 

Marezzo .—Marezzo artificial marble manufactured 
from plaster or Keen’s cement and mineral coloring mat¬ 
ter is made in wood or plaster moulds for moulded work, 
and on slate or glass benches if in slabs. If thick plate 
glass is used, the worker has the advantage of being able 
to look through it to see if the figure of the work re¬ 
quires altering. Glass also has the advantage of leaving 
a smoother and more polished face. All wood and 
plaster moulds should be got up with a good face, and 
properly seasoned, to save stoning and polishing the face 
of the work. Keen’s cement may be used advantageous¬ 
ly in making Marezzo, especially for chimney pieces, or 
other works required for exposed positions. Keen’s 
cement for Marezzo should be of the highest class. If 
the cement is not of the best, it will effloresce, rendering 
the work of polishing difficult, if not spoiling it alto¬ 
gether. Keen’s cement requires no size water, but in 
gauging either Keen’s or plaster, no more should be 
gauged than can be conveniently used. The quantities 
of colors, Keen’s cement, plaster, and size water should 
be measured and gauged pats kept for future reference. 


278 


CEMENTS AND CONCRETES 


All gauge-pots snould be of earthenware, as they are 
more easily cleaned out, and do not rust, as is the case 
with metal pots. All the tools should be kept bright and 
clean, as when working scagliola. 

Marezzo is made in the reverse way to scagliola, as the 
face or marble is put in the mould first, and the core or 
backing put on afterwards. 

All the mineral colors should be of good quality, in 
fine powder, and ground in water, known as “pulp. A 
number of basins should be handy, and there should be 
a supply of twist silk in skeins varying in diameter from 
Vs to % of an inch, and cut into lengths of 14 to 18 
inches. For common work, good long flax fibre may be 
used. Canvas is also required. One end of the silk or 
fibre skein must be knotted. These are known as “drop 
threads. ’ ’ 

After the moulds are made, seasoned, and oiled, the 
young hand may begin by trying to make some easy 
marble, for a slab or chimney-piece. Gauge Keen’s extra 
superfine cement or superfine plaster, in a large basin 
labelled No. 1, well mixing it until about the consistency 
of cream. This is pure white. Now pour a small quan¬ 
tity of this white plup into two small gauge-pots, Nos. 
3 and 4. Pour a third of what remains in the No. 1 
pot into another gauge pot, No. 2. Take some black- 
colored pulp, and make No. 1 a blackish-grey. Color 
in the same way No 2. only very much blacker than 
No. 1. No. 3 is now slightly tinted with pulp from No. 
1. This leaves No. 4 pure white. Then take a skein of 
twist (or threads), dip into No. 4, the pure white, and 
well charge it by stirring it about with the fingers; take 
out the threads, taking each end between the thumb and 
forefinger of each hand, and with the remaining fingers 
of each hand separate the threads, allowing plenty of 


MISCELLANEOUS MATTERS 


279 


“swag,” and strike this into the face of the mould, mak¬ 
ing each stroke at different angles, recharging the 
threads when necessary. Repeat this process with pulp 
from No. 3, but in a lesser quantity; then dip your 
finger ends into No. 2, and fling drops about the size of 
large peas all over the veining. These drops must be 
thrown on with considerable force, so as to cut into the 
veins as much as possible. Dip the fingers into No. 
1, and throw on No. 2, using alternately from each gauge- 
pot until yon get a uniform thickness of surface (scag), 
about y 8 inch in thickness. Now run a trowel over this 
to lay down any ridges. Cover the work with a piece 
of canvas, laying it evenly, smoothly, and without 
wrinkles. Be careful to put the canvas in the proper 
place, as moving it would spoil the lines of the veining; 
then spread a quantity of dry coarse Keen’s lightly over 
the entire surface. This will absorb any superfluous 
moisture through the canvas. After the canvas and 
coarse Keen’s have lain from ten to twenty minutes, or 
according to the stiffness of the gauge of the marble, the 
canvas and coarse cement are easily lifted off. Should 
any portion of the face of the scag leave the mould, and 
adhere to the canvas, it is taken off and put back in 
its place in the mould. The whole surface is now 
trowelled to render it dense and hard. The moisture 
should be sufficiently absorbed, or the trowelling may 
spoil the figure. The proper absorption of the moisture 
by the dry cement through the canvas, and well trowel¬ 
ling, are most essential to good work, ensuring hardness 
and density. 

The core or backing is now made by using the coarse 
Keen’s previously used for absorbing the moisture from 
the face, gauging it with some fresh coarse Keen’s as 
stiff as possible. This is laid on as thick as required. If 


280 


CEMENTS AND CONCRETES 


the face of the scag be very dry, spread a thin coarse 
ganged Keen’s, so as to give a perfect cohesion between 
the marble and the backing. The flat surface of the 
backing should always be ruled or floated straight with 
a uniform thickness, so as to give a true bed for the cast 
when it is taken out of the mould, and laid on a bench 
ready for stoning, stopping, and polishing. This can 
be done as soon as it is thoroughly set and hard, and in 
the same manner as scagliola. 

Marbles having long stringy veins require a different 
method of putting in the veins. Take the skeins, or 
4 ‘threads,” by the knot with one hand, and thoroughly 
saturate them with the veining mixture, and run the 
finger and thumb of the other hand down the threads 
to clear them of any excess of veining color with which 
they may be charged. Then give the end not knotted to 
your partner, holding the knot in your left hand. Pull 
the threads asunder, so as to take the form of the veins 
of the marble you are copying, then lay them in the 
mould, leaving the knots hanging over the edge of the 
mould, or at least visible, to facilitate their removal 
when required. The threads should be arranged on the 
mould so as to take the form of the veining. The other 
colored materials are then thrown upon the thread veins, 
which quickly absorb the coloring matter from them; 
care being taken that the various colors are thrown or 
dropped from the finger tips, to form the figure of the 
body of the marble that is being copied. When the 
mould is sufficiently and properly covered with the 
marbling, take hold of the knots and withdraw the 
threads. These should be cleaned by passing down the 
finger and thumb for future use, saving the superfluous 
stuff for filling up any holes in the marbling. The 
absorption of the use of canvas and dry coarse Keen’s, 


MISCELLANEOUS MATTERS 


281 


and the filling in of the backing or core, is then 
proceeded with as before described. 

Granites, porphyries, etc., are made in a different 
manner. For porphyries with white and black specks, 
make a slab of white Keen’s about % inch thick, and 
another in black, the same thickness. When they are 
set and hard, chop them into small pieces, then run them 
through a sieve, having a mesh to let through the pieces 
of the required size only. The pieces retained in the 
sieve can be broken and sieved again. The whole is 
now sieved again through a smaller mesh, which re¬ 
tains only the size wanted. The refuse can be used for 
small work or backing up. When the gauged stuff for 
the facing is mixed of the required tint (a reddish- 
brown), damp the black and white specks with the 
gauged color by means of a trowel and rolling, care 
being taken not to break the edges and faces of the 
black and white specks. When it is well mixed, lay it 
onto the face of the mould about 3-16 inch thick, press¬ 
ing it as firmly and evenly as possible. Then absorb the 
moisture by means of canvas and dry coarse Keen’s, 
trowel it well to give density, and fill in the backing or 
core as before. For 11 Rouge Royale, ” “Verd Antique, ’ ’ 
&c., requiring large white patches of irregular size, the 
sieving can be dispensed with. The white pieces are 
broken haphazard, and pieces of alabaster can also be 
inserted in these, and many other marbles, due regard 
being given to the size and quantity, so as not to produce 
an unnatural effect. The remainder of the figure is 
formed with the “drop threads,” and the other colors 
being thrown cn. 

From this description of Marezzo, the workman will 
understand that in the case of marbles classed as “Brec¬ 
cias,” such as “Roitge Royale,” “Black and Gold,” &c., 


282 


CEMENTS AND CONCRETES 


having patches and rough jagged veins in them, he must 
have flat pieces of the required color previously made 
and broken up, or alabaster, as the case may be inserted 
into them, and the veining done with the “drop threads” 
and that fine or long veining threads are not required; 
that unicolored marbles require no veining threads; that 
the long veined marbles, require the long threads, and in 
some cases the “drop threads” as well, and that granites, 
porphyries, &c., require no threads; that black is diffi¬ 
cult to make owing to the pure white cement requiring so 
much color; and finally, that in all cases, whether Ma- 
rezzo or scagliola, the polishing is done in a similar man¬ 
ner, whether using plaster or Keen’s cement. 

The details given must be carefully followed to pro¬ 
duce work artistic in figure and appearance. The direc¬ 
tions for making “St. Ann’s” so far as manipulation is 
concerned, apply to all others. A little patience, prac¬ 
tice, and perseverance will soon give confidence and ex¬ 
pertness in producing sound scagliola and Marezzo. 

Granite Finish .—Granite is a peculiar finishing coat of 
plaster which is sometimes used in this country to imi¬ 
tate granite. For granite finish, first render the walls 
with hydraulic lime, and when nearly dry lay with a thin 
coat of the same material but colored light brown. Then 
while this coat is still moist, splash the surface lightly 
with white stuff, then with black stuff, using only half 
as much as used for the white stuff. The red stuff is 
best applied by dotting the surface with a small brush 
charged with the colored stuff. After these colored lime 
stuffs are firm, but not set, the surface is carefully trow¬ 
elled, using the minimum of water so as not to mix the 
various colored stuffs. The surface is sometimes left in a 
rough state, or as left when splashed. After the surface 


MISCELLANEOUS MATTERS 283 

is firm, it is set out and jointed to represent blocks of 
graite. 

Granite Plastering .—Granite plastering is a method, 
introduced by the author, to imitate granite. This mode 
of imitating granite is based on the scagliola process. It 
is also somewhat similar to the granite finish, and gives 
better and more reliable results. 

The method of executing granite plaster work is as 
follows: First select the most suitable lime or cement 
for the situation, such as Portland cement or hydraulic 
lime for exterior work, and Parian or other white cement 
for interior work. Having decided on the material, 
gauge three different colored batches, one white, one red, 
and one black, taking care that the stuff is gauged stiff 
and expeditiously so as to obtain a hard substance. The 
material is colored to the desired shades, as described 
for scagliola or colored stuccos. When gauged the stuffs 
are laid separately on a bench and rolled until about 
3-16 inch thick, and when nearly set they are cut into 
small irregular cubes and allowed to set and harden. The 
wall is then floated, ruled fair, and the surface keyed, 
and when set it is laid with a thin bedding coat of simi¬ 
lar stuff used for the floating, but colored light brown. 
The colored cubes are then mixed together in due propor¬ 
tions, and gauged with a portion of the light brown col¬ 
ored stuff and laid on the thin coat while it is soft. The 
whole is then firmly pressed with a hand-float until a 
close, compact, and straight surface is obtained, taking 
care when pressing the stuff not to break the cubes. 
After the stuff is set and perfectly dry and hard, the 
surface is rubbed down and polished, as described for 
scagliola or for marble plaster. The bedding coat should 
be sufficiently thick to receive the colored cubes, other¬ 
wise the larger cubes will project at parts, and cause 


284 


CEMENTS AND CONCRETES 


extra labor in making a uniform and straight surface. 
Unless the cubes are fairly level when pressed, the sur¬ 
face will have a spotty appearance, besides being more 
difficult to polish. Where expense or time is a consid¬ 
eration, a striking appearance is obtained at less cost 
than polished work, by simply finishing the surface with 
a cross-grained hand-float, and a semi-polished surface is 
obtained by trowelling, or by scraping the surface with 
a joint-rule. Grey or light-colored granites are imitated 
by altering the colors of the cubes and the bedding coat 
as desired. Bold and striking effects on wall surfaces 
can be obtained by a combination of different colored 
granites, laid out in bands and borders. The effect can 
be increased by the introduction of borders in sgraffito, 
with the bands in granite plaster. 


PART II 


CEMENTS AND CONCRETES, AND HOW TO USE 
THEM. 

It is not necessary to the workman that he should ex¬ 
pend a long period of his valuable time in reading up 
the history of cements and concretes, nevertheless it is 
proper he should be acquainted with the outlines of the 
origin, growth, and development of cements, concretes 
and their uses, and to this end the following brief his¬ 
torical summary is presented, sufficient to give the work¬ 
man a fair idea of the beginning and growth of the use 
of cements and concretes: 

The word concrete is of Latin origin, and signifies a 
mass of materials bound or held together by a cementing 
matrix. The Romans used concrete B. C. 500. They 
made good use of lime concrete both in the construction 
of buildings and roadways. “Roads,” says Gibbon, 
“were the most important element in the civilization 
of ancient Rome; and the cost of the Appian Way was 
such as to entitle it to the proud designation of ‘Re¬ 
gina Viarum’ (the Queen of Roads).” The Appian 
(the oldest of the Roman highways) was commenced by 
Appius Claudius Caius, when he was censer, about three 
centuries before the birth of Christ. It extended from 
Rome to Capua, whence it was consequently carried on 
to Tarentum and Brundusium. Antonio Nibby, an 
archaeologist of the highest authority, states that the 
Appian Way had an admirable substructure, with lime 
concrete materials superimposed, and large hexagonal 
285 


286 


CEMENTS AND CONCRETES 


blocks of stone laid on the top of all. The Romans built 
concrete aqueducts, often several miles long, to convey 
water to the cities. The palace of Sallust, the historian, 
was built about B. C. 50, and was frequently used as a 
residence by most of the emperors until as late as the 
fourth century. It was partly burnt by Alaric in the 
year 410. This once magnificent edifice was erected on 
a strange site, partly in the valley at the%foot of the 
Quirinal Hill, and partly on the top of the hill. The 
latter portion of the palace, which was of great extent, 
has been almost wholly destroyed by the builders of the 
modern boulevard. The walls, which were thick and 
high, were most valuable examples of the Roman use of 
concrete, unfaced by brick or stone. There is still visi¬ 
ble evidence, in the form of impressions left on those 
walls, which clearly demonstrates their method of cast¬ 
ing walls in situ by means of wood framing. Rows of 
timber uprights, about 10 feet high, 6 inches wide, and 
3 inches thick, were fixed along both faces of the in¬ 
tended wall. Boards about 10 inches wide and 1% 
inches thick, in suitable lengths, were then nailed hori¬ 
zontally along the uprights, thus forming two parallel 
wooden walls, into which the concrete was laid and 
rammed until the space between the boards was filled 
to the top. "When the concrete had set, the wood fram¬ 
ing was removed, and refixed at the top of the concrete, 
the whole process being repeated until the wall was 
raised to the required height. This concrete was far 
more durable than brick or stone. The jerry-builders of 
the modern Rome had no difficulty in pulling down the 
stone wall of Servius, but the concrete walls required the 
use of dynamite to complete their destruction. After 
withstanding the wear and tear of many centuries, and 
the repeated onslaughts of the Goths and Vandals, it was 


HOW TO USE THEM 287 

left to the nineteenth-century speculative builder to de¬ 
stroy those interesting remains. 

The use of concrete for floors and roofs is of great an¬ 
tiquity. It was employed for this purpose by the Ro¬ 
mans in the time of Julius Caesar. Professor Middleton, 
in his first book, “Ancient Rome,” states that the whole 
of the upper floor of the Antrium Vesta is formed of a 
great slab of concrete, 14 inches thick, and about 20 feet 
in span, merely supported by its edges on travertine cor¬ 
bels, and having no intermediate supports. In his sec¬ 
ond book, “The Remains of Ancient Rome,” Professor 
Middleton mentions that the Romans used concrete for 
the construction of the Pantheon, which was erected 
about the time of Christ. A curious and apparently un¬ 
accountable feature as regards practical purposes is that 
the concrete is faced with bricks, which were faced again 
either with stucco or (in special cases) with marble 
veneer. The Professor gives a sketch showing the ex¬ 
terior facing and the section of a wall of this kind, the 
entire mass being composed of concrete, except a facing 
of thin bricks, triangular in plan, with the points in* 
wards. As the author observes, these bricks could not 
possibly be intended as a matrix for concrete, as it would 
not have withstood the pressure of the latter while in a 
wet state. It must therefore have been necessary to re¬ 
tain the brick and the concrete with an external tim¬ 
ber framing, as in the case of unfaced concrete. There 
could be no gain of strength or other benefit to compen¬ 
sate for the time expended setting the brick skin. The 
dome of the Pantheon is 142 feet in diameter and 143 
feet high. This is also formed with brick-faced concrete. 
It has often been described and even drawn by various 
authors as essentially a brick dome. Professor Middle- 
ton remarks there must have been very elaborate con- 


288 


CEMENTS AND CONCRETES 


struction of centring for this and other massive concrete 
vaults. He states they employed a method, which has 
become common of late, to avoid the necessity of build¬ 
ing up the centring from the ground. They set back 
the springing of the arch from the face of the pier, so 
as to leave a ledge from which the centring was built, 
the line of the pier being afterwards carried up until it 
met the intrados of the arch, leaving it a segmental one. 
The Professor also found signs of timber framing for 
walls in the remains of the Golden House of Nero, un¬ 
der the Thermae of Titus, where, he says, “the chan¬ 
nels formed by the upright posts are clearly visible. 
These upright grooves on the face of the wall are about 
6 inches wide by 4 inches deep, and they are afterwards 
filled up by the insertion of little rectangular bricks, so 
as to make a smooth unbroken surface for the plaster¬ 
ing. ” This method is difficult to understand. Accord¬ 
ing to the present practice, the supports should be fixed 
outside the line of wall surface and leave no space to 
fill in afterwards. He also mentions a striking example 
of the tenacity of good concrete in the Thermae of Cara- 
calla, at a part where a brick-faced concrete wall origin¬ 
ally rested on a marble entablature supported by two 
granite columns. “In the sixteenth century,” he says, 
“the columns and the marble architrave above them were 
removed for use in other buildings, and yet the wall 
above remains, hanging like a curtain from the concrete 
wall overhead.” This proves that the Romans bestowed 
as much thought and care on the materials and their 
composition as they did on their construction. Profes¬ 
sor Middleton notes that the larger pieces of aggregate in 
the concrete, which are not close together, are so evenly 
spaced apart as to lead to the conclusion that they must 
have been put in by hand, piece by piece. 


HOW TO USE THEM 


289 


Dr. Le Plongeon, during his explorations in Peru, 
found many remains of mud concrete walls. Although 
they were built many centuries ago, they have proved 
sufficiently durable to exist until to-day. The materials 
were placed between two rows of boards, and well beat¬ 
en, and the exteriors were sometimes decorated with plas¬ 
ter work. Thus it appears that the Peruvian builders of 
the period of the Incas anticipated by centuries the 
method (but not the material) of our modern concrete 
buildings. Le Plongeon’s researches conclusively estab¬ 
lish the fact that these Indians were masters of concrete 
building and plastering. The walls of the fortress of 
Ciudad Rodrigo in Spain are built of concrete. There 
are over twelve miles of arches and tunnels constructed 
with concrete in the Yarone Aqueduct, which supplies 
Paris with water. One of the arches over the Orleans 
Road, in the Forest of Fontainebleau, has a span of 125 
feet without a joint, the arches and the water-pipe or 
tunnel being entirely composed of beton, made with 
Portland cement, hydraulic lime, and the sand found on 
the spot. Concrete blocks weighing over 20 tons were 
used in the construction of the Suez Canal, 3,000,000 
tons of these blocks being required at Port Said alone. 
Besides the unquestionable durability of concrete, it also 
possesses fire-resisting and waterproof powers of the 
highest degree. Constructional works formed with con¬ 
crete carefully made and applied may be considered ab¬ 
solutely fire-resisting and damp proof; in fact, in these 
respects concrete has long since passed the experimental 
period, inasmuch as numerous tests, under the most try¬ 
ing and adverse circumstances, attest the superiority of 
this material for sanitary and durable work. 

The best concrete in France is that made under Coign- 
et’s system of “ beton agglomere,” and has been used 


290 


CEMENTS AND CONCRETES 


with great success in the construction of various large 
and important works. In Paris many miles of the sew¬ 
ers have been formed of this material, and a church in 
the Gothic style, from the foundations to the top of the 
steeple (which is 136 feet high) is entirely formed of 
beton. The work was prosecuted without cessation for 
two years, and was exposed to rain and frost, but has not 
suffered in the slightest way from the extremes of tem¬ 
perature. The strength of this material for constructive 
work may be judged by the thickness, or rather want of 
thickness, in the construction of a house, six stories high, 
having a Mansard roof—cellar, 19 inches, first story, 15 
inches; second story, 13 inches, and diminishing 1 inch 
every successive story, so that the sixth story was 9 
inches. The cellars have a middle wall from back to 
front, from which spring flat arches having a rise of one- 
tenth of the span, the crown being 5 inches thick, and 
at the springing 9 inches, which formed strong damp- 
proof and fireproof cellars. There are many houses in 
Paris, and this country, constructed of this material. It 
has been used in London in the construction of sewers, 
&c. This concrete is composed of Portland cement, 
sand, and lime. Hydraulic lime is used for sewers and 
waterworks, and common lime for ordinary work. The 
lime is used in a powdered state. The whole of the ma¬ 
terials are mixed in a dry state by hand, and afterwards 
gauged in a specially made pug-mill. The least possible 
amount of water is added by means of a fine jet while the 
pug-mill is in motion. The mixture is then spread in 
thin layers, and beaten by rammers formed of hardwood. 
The quantities for coarse work, where a fine face is not 
required, are: Portland cement, 1 part; common lime, 
y 2 part; gravel, 13 parts; coarse and fine sand, 6 parts. 
And for sewers: Portland cement, 1-5 part; hydraulic 


HOW TO USE THEM 


291 


lime, 1 part; sand, 6 parts. And for external work of 
good quality: Portland cement, 1 part; lime, % part; 
sand, 7 parts. The above proportions are all by meas¬ 
ure. Specimens of Coignet beton at two years old have 
attained a crushing strength of 7,400 lbs. to the square 
inch. 

Fine Concrete .—“No book on plastering,” says Miller, 
“would be complete without a description of the meth¬ 
ods for working ‘fine concrete’ (here termed ‘fine con¬ 
crete’ to distinguish it from rough concrete as used for 
foundations, &c.), which is now coming into general use 
for paving purposes, staircases, and constructive and 
decorative works for buildings. Floors, roofs and simi¬ 
lar works which are finished with fine concrete, being 
within the plasterer’s province, also demand description. 
The proper manipulation of the plastic materials, which 
is imperative for sound concrete, is undoubtedly plaster¬ 
er’s work. The higher branches of concrete work, for 
architectural construction and decoration, embrace 
model-making, modelling, piece-mblding and casting. 
Concrete construction is therefore essentially a part and 
parcel of the plasterer’s art and craft. The construc¬ 
tion of concrete staircases in situ affords a striking ex¬ 
ample of the necessity of employing plasterers. Only a 
plasterer can manipulate the materials correctly, make 
the nosing mitres sharp and true, and set the soffits of 
the stairs and landings, and form a true arris at the 
stringing, whereas the non-plasterer leaves the work un¬ 
even, rough and unsound. The non-plasterer can just 
manage to spread the stuff laid on the ground for him 
when laying paving, but he is entirely lost when the 
stuff has to be taken up on a hawk and laid with a 
trowel on an upright or overhead surface. He then gets 
upset, or rather he upsets the stuff. The non-plasterer 


292 


CEMENTS AND CONCRETES 


possibly may have been an unfinished apprentice, or a 
dunce at his former trade, hence his trying another. 
These remarks are not caused by any hostility to other 
trades, but are inspired by the fact that many failures 
in the better class of concrete are due to the non-plaster¬ 
er’s incapacity in working, and his lack of knowledge of 
the materials. Portland cement concrete pavements were 
first used about sixty years ago. Its introduction, im¬ 
provements, and subsequent rapid strides for paving, 
and in the construction of staircases, cast and made in 
situ, are due to the plasterers. Concrete is one of the 
best materials for paving the sidewalks of streets, abat¬ 
toirs, stables, breweries, &c. It is jointless, impervious, 
non-slippery, and can be laid with a plain surface or 
grooved to any desired form. The only objection to 
paving laid in situ for streets is that when it is cut to 
repair or alter gas or water pipes it is difficult to make 
it good without the patches showing. This slight defect 
can easily be overcome by cutting out the whole bay 
where the patches are, or by forming a movable slab 
over the pipes. 

There has been in recent years some controversy as 
to the department of the building trades to which lay¬ 
ing concrete paving properly belongs. The claim is un¬ 
doubtedly upheld in the strongest way for the plaster¬ 
ers. A further argument, if one is needed, to identify 
the operation as a plasterer’s job, is that the tools, skill 
in which is necessary, are exclusively those of plaster¬ 
ers. The laying trowel and the hand-float are prin¬ 
cipally used, and none but plasterers exclusively employ 
them, no other workman in any branch of the building 
trades being habituated to their use. In every part of 
the world where concrete paving has been used it has 


HOW TO USE THEM 


293 


been laid down by plasterers, so that it may be looked 
upon as their legitimate sphere of work. 

Concrete is now extensively used in preference to 
earthenware for making sewer tubes. Experience has 
proved that the acids present in liquid sewage and the 
gases generated by the action of a faecal decomposition 
do not injure the concrete tubes, but on the contrary tend 
to harden them. Among the many unlikely purposes for 
which concrete has come into use may be mentioned stat¬ 
uary, vases, fountains, sinks, tanks, cisterns, cattle- 
troughs, silos, railway sleepers, platform copings, man¬ 
telpieces, chimney pots, tall chimneys, tombs, tombstones, 
and coffins. Concrete is slowly but surely coming to the 
front as one of the most useful, economical, constructive, 
and decorative materials for works requiring strength 
and endurance. It may now be said to be indispensable 
to the architect, engineer and builder. Concrete, when 
properly made with a Portland cement matrix, and slag 
or a similar aggregate, is undoubtedly the best fire-proof 
material used in any building construction. It can be 
made thoroughly waterproof and acid proof, and may be 
moulded or carved to any design and colored to any 
shade. After this brief historical review of concrete, the 
practical considerations of the modern working by plas¬ 
terers claim attention. Before describing the methods 
of working the concrete, a description of the materials, 
with their characteristics and application, is given as a 
preliminary guide and reference. 

Matrix .—Matrix is a word used to designate any ma¬ 
terial having a setting, binding, or cementing power, 
such as limes, plaster or cements. For concrete paving, 
stairs, floors, or cast work for external purposes, it may 
be truly said that there is only one matrix, namely, Port¬ 
land cement. 


294 


CEMENTS AND CONCRETES 


Aggregate .—This is a term applied to those materials 
held or bound together by the matrix. Aggregates may 
be fibrous or non-fibrous, natural or artificial. The nat¬ 
ural aggregates comprise granite, stone, shells, marble, 
slate, gravel, sand, metal filings, &c.; the artificial slag, 
brick, pottery, scharff, clinkers, coke-breeze, ashes, glass, 
&c.; and the fibrous slag, wool, coir, fibre, reeds, hair, 
cork, tow, chopped hay, straw, shavings, &c. The fibrous 
aggregates while being principally of a natural kind, are 
generally of a vegetable nature. They are commonly 
used with a plaster matrix for the interior works. The 
best aggregates for the upper coat of concrete paving 
are granite, slag, and some of the hard limestones. The 
best and cheapest for the first layer or rough coat are 
broken bricks, old gas retorts, clinkers, whin and other 
stones. Stone chippings from masons’ yards and quar¬ 
ries are .cheap and good. Shingles and gravel are also 
used, but owing to their round and smooth surfaces they 
afford little or no key for the matrix. When found in 
large quantities and at a cheap rate, they should be 
broken to render them more angular, so as to give a bet¬ 
ter key. Aggregates are broken by a crushing or stamp¬ 
ing machine. In Paris, the stone aggregates used for 
casting figures, vases and similar ornamental works is 
generally broken by hand. 

Aggregates should be clean, and their surfaces free 
from mud and dust. Coarse aggregates are easily 
cleaned by turning on a strong stream cf water from the 
hose. The aggregates should be laid on an inclined plane 
to allow the water and dirt to run off. The importance 
of a clean aggregate is seen from the fact that briquettes 
made from washed particles resist a tensile strain from 
15 to 20 per cent, higher than those made from unwashed 
particles, when tested under similar conditions. 


HOW TO USE THEM 


295 


Porous Aggregates .—All aggregates of a porous na¬ 
ture or having a great suction should be well wetted 
before being gauged, to prevent absorption of the water 
used for gauging the matrix. A porous aggregate re¬ 
quires more cement than one of closer texture, and is 
not as strong. Water has no power to harden or set an 
aggregate. It is used to render the mass plastic, and to 
set the cement. No more than is necessary for this pur¬ 
pose should be used. Sloppy cement will not attain the 
same degree of hardness as a firm or stiff gauged cement, 
consequently it stands to reason that if the water or a 
part of it be absorbed by a porous aggregate, it will ren¬ 
der the matrix, or that part next to the aggregate, friable 
and worthless. This may be proved by gauging a part 
of neat cement and spreading it on a brick and another 
part on a slate. It will be found that the latter will set 
and become hard, whilst the former will either crumble 
before setting, or partly set, without getting hard. All 
aggregates are more or less absorbent, but while the por¬ 
ous kinds will absorb the water from the matrix, not 
only leaving the portions in immediate contact with the 
aggregate inert, but also weakening the whole body of 
the concrete, the non-porous have little or no absorption, 
water being retained in the matrix, or a portion may lie 
on the surface of each particle of aggregate, thus tend¬ 
ing to harden the matrix and increase the general 
strength of the concrete. It may be thought that these 
defects are trivial, and can be overcome by thoroughly 
saturating the porous aggregate to prevent suction, but 
the fact still remains that after this or other excess water 
has dried out, the body of the concrete must still be por¬ 
ous, and this is one, if not the principal reason, why 
some concretes are not damp-proof. The quantity of 
matrix used for ordinary concrete being very much less 


296 


CEMENTS AND CONCRETES 


than the quantity of aggregate, and the matrix not being 
of sufficient thickness to resist the force of atmospheric 
moisture, the damp finds a ready passage through the 
porous portions. A mass of porous aggregate will ab¬ 
sorb external moisture, and this will gradually work 
through the body to the weakest or driest surface, or be 
retained for a time, according to the state of the atmos¬ 
phere. The extra keying power claimed for a porous 
aggregate is infinitesimal. It may be said not only to be 
of no value, but unnecessary, bearing in mind that in 
well-made concrete every particle of aggregate is envel¬ 
oped with matrix. 

Another point to be considered is the great tenacity of 
Portland cement to most clean surfaces, however smooth. 
Many men will have noticed how it clings and adheres 
when set to iron, even to the smooth blades of trowels 
and shovels. The ultimate tenacity of neat Portland 
cement after being gauged twelve months is about 500 
lbs. per square inch. 

Compound Aggregates .—The proper selection and use 
of aggregates for a true concrete is not secondary, but 
of equal importance to the matrix. As inferior aggre¬ 
gates are in the majority, it is advisable to take their de¬ 
fects into consideration. For concrete floors, roofs, and 
stairs, where strength, durability, and fire resisting prop- 
erites are imperative, gravel and coke-breeze as aggre¬ 
gates stand lowest in the scale. Owing to their abun¬ 
dance and cheapness, however, or for want of better ma¬ 
terials, their use is often unavoidable. Their individual 
defects may be partly if not wholly corrected by a com¬ 
bination of two or more aggregates so as to balance their 
respective good and bad qualities. It is self-evident that 
the hard, non-porous, and incombustible nature of gravel 
will correct the soft, porous, and combustible nature of 


HOW TO USE THEM 


297 


coke-breeze, and that the light, rough, angular, and elas¬ 
tic nature and variety of size of coke-breeze will counter¬ 
balance the disadvantages of the heavy, smooth, round, 
and rigid nature and uniformity of size-of gravel. The 
strength, irregularity of size, and form of broken bricks 
and its incombustible nature, causes it to be a direct gain 
to either of the above. The mixing of various aggre¬ 
gates may seem of small importance, but if by their judi¬ 
cious amalgamation the strength is enhanced, or the 
weight or cost of the material decreased, or gained, if the 
practice enables any waste or by-product to be utilized, 
then the advantage becomes obvious. To argue by 
analogy, it is well known that it is by the judicious com¬ 
bination and manipulation of various materials that 
mortars and cements attain their strength and hardness, 
therefore the same course will give equally good results 
with concretes, while rendering economy with safety pos¬ 
sible. 

The compressive and tensile strength of concrete is 
influenced both by the matrix and the aggregate. Aggre¬ 
gates which are uniform in size (or if of various sizes 
which are not graduated in proportion to each other), or 
having their surfaces spherical, soft or dirty, will not 
bind with the matrix, or key or bend with each other, so 
well as those which are of various graduating propor¬ 
tional sizes, and have their surfaces hard, angular and 
clean. 

Sand and Cement .—Sand is extensively used as an 
aggregate in Portland cement for cast work, mouldings, 
and wall plastering. Fine sand does not give so good 
results for strength as coarse sand, and a hard-grained 
sand is more durable than a soft one. Ground brick¬ 
bats or pottery, sandstone and flints, fine gravel, smithy 


298 CEMENTS AND CONCRETES 

ashes, and coke-breeze are often used as substitutes for 
sand. 

It has generally been assumed that sharp coarse sand 
is one of the best and strongest for gauging with cement, 
but, according to experiments made by Mr. Grant, clean 
sharp pit sand gives better results, as he found that 
whereas test briquettes having a sectional area of 2 y 2 
superficial inches, composed of equal proportions of 
coarse sand, broke at the end of twelve months with a 
tensile strain of 724 lbs., it required 815 lbs. to break 
briquettes composed of equal parts of cement and pit 
sand. With reference to various sands suitable for mak¬ 
ing mortar with cement, Mr. Grant’s experiment is of a 
most surprising nature, as it indicates that sand made 
from ground clay ballast, or ground brick—which are 
identical—and Portland stone dust, were superior to pit 
or sea sand, or smiths’ ashes. 

Th$ following shows the results of tests of various 
aggregates made by Lieutenant Innes. The briquettes 
are composed of Portland cement, sand, or other aggre¬ 
gates, in the proportions of 1 to 2, and were kept in 
water for seven days. 

It will be seen that Portland stone dust gave the best 
results, and the others follow in this order—coarse sea 
sand, rough pit sand, smooth pit sand, drifted sea sand, 
and lastly smithy ashes. If the dust had been elimi¬ 
nated, the tests would be more valuable. The degree of 
coarseness has a considerable influence on the strength 
of the concrete and mortar. Fire sand makes weaker 
mortar than coarse. The following table gives the re¬ 
sults of two series of tests carried out by Mr. Grant. 
The cement was sifted through a sieve with 2,580 meshes 
to the square inch, and was made into briquettes with 2 


Tests of Various Sands, &c., and 


HOW TO USE THEM 


299 


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300 CEMENTS AND CONCRETES 

parts of sand by weight. All the briquettes are kept in 
water. 


Tensile Tests of Portland Cement and Sand (Coarse 
and Fine). 


No. 

- 

Sand 

tested 

by 

Sieves. 

At 28 
days. 

60 

days. 

91 

days. 

182 

days. 

273 

days. 

364 

days. 


First Series — 

Nos. 

lbs. 

lbs. 

lbs. 

lbs. 

lbs. 

lbs. 

1 

1 cement to 3 sand. 

20-30 

78.5 

113.9 

116.9 

142.3 

178. 

205.5 

2 

ditto. 

10-20 

137.1 

239.5 

223. 

231.5 

254.5 

251.5 


Second Series — 








3 

1 cement to 3 sand. 

20-30 

117.2 

134.5 

145. 

156. 

157.8 

213. 

4 

ditto. 

10-20 

212. 

236.5 

206. 

253. 

267.5 

273.5 


In the above each figure is the average of ten tests, 
the result being given in pounds per square inch. The 
sand used in tests 1 and 3 passed a sieve with 400 meshes 
to the square inch, and the sand used in the tests 2 and 
4, through a sieve with 100 meshes to the square inch. 

Fireproof Aggregates .—The selection of the best 
known fire-resisting aggregate for fire-proof concrete 
construction is of vital importance. Granite, stone, and 
flints splinter and crack when subjected to great heat, 
or to the sudden reaction caused by cold water used for 
extinguishing fires. Coke-breeze concrete, when under 
the influence of intense heat, as for example in the midst 
of a building on fire (stated by Captain Shaw to be 
from 2000 degrees to 3000 degrees Fahr.), will gradually 
calcine and crack, and finally fall to dust. 

Slag is one of the best fire-proof aggregates. It is a 
well-worn axiom that “what has passed through the fire 













HOW TO USE THEM 


301 


will stand the fire. ’ ’ There is no other material that has 
passed the ordeal of fire like slag. Its great hardness, 
density, and angularity (when crushed) all tend to make 
it one of the best substances for fire-proof construction. 
Slag is cheap and abundant, but requires great care in 
selection, as some kinds contain a large amount of sul¬ 
phur, which is very detrimental to Portland cement, 
causing the concrete to blow and expand. The presence 
of sulphur can often be detected by the smell alone. 
When sulphur is present in a heap that has lain for 
some time, or sufficiently long to allow the atmosphere to 
cleanse the outer surface, it is more difficult to detect. A 
hole should then be dug in the heap, and the presence 
of sulphur can be ascertained by smell, heat, and color. 
It will smell strong, and if new will be warm, and show 
yellow patches. The power of the sulphur is so great 
that washing the slag once will not entirely cleanse it. 
In some cases frequent washings and long exposures to 
the air are necessary. There are some slags that are free 
or nearly so from sulphur, and which can be had direct 
from the iron furnaces. The slag from coal and iron 
furnaces is largely employed for concrete paving. It is 
hard and practically free from sulphur. The best size 
is % inch screenings. This when sifted yields a fine kind 
for topping, and the residue is useful for the rough coat. 

The next best fire-resisting aggregates are fine-bricks, 
pottery, scharff, hard clinkers, and pumice-stone. The 
last has the advantage of being extremely light, but it is 
too soft for the frictional wear. Coke-breeze may to a 
certain extent be deprived of its combustible nature and 
rendered more fire-resisting by washing and passing it 
through a inch sieve, then adding 1 part flowers of 
sulphur and 10 parts fine broken bricks to 20 parts of 
«oke-breeze. The larger breeze rejected by the sieve can 


302 


CEMENTS AND CONCRETES 


be broken small, or used for internal layers of concrete. 
The bricks should also be passed through a % inch sieve. 
The finer the breeze and brick, the better for receiving 
and retaining nails. 

Voids in Aggregates .—The quantity of voids or in¬ 
terstices depends on the shape and size of the aggregates. 
The least quantity of voids will be found in those aggre¬ 
gates which are broken small, and contain pieces of va¬ 
rious sizes. Gravel free from sand contains about 30 
per cent, of voids, and broken stone of Uniform size about 
50 per cent. Sand is often mixed with gravel, stones, 
&c., to lessen the quantity, or fill the voids, so as to en¬ 
sure the full strength of the concrete, without adding 
more cement than the proper ratio. The following 
method is used to ascertain the voids in aggregates:— 
Fill a box of known capacity with damp, broken aggre¬ 
gate ; start shaking it during the operation; then fill the 
box to the brim with water; the quantity of water is the 
measure of the voids in the aggregate. Having now 
briefly reviewed the characteristics of the aggregates 
most used, the practical conclusions to be drawn are that 
they should be angular in form, hard in nature, grad¬ 
uated in size, and clean. 

Crushing Strength of Concrete .—The crushing 
strength of concrete depends upon the ratio of cement, 
and the nature of the aggregate. Another important 
factor is compression, done by heating and ramming. 
Compression increases the weight of concrete about 4 per 
cent., and the strength about 25 per cent. The follow¬ 
ing table shows the crushing strength of concrete made 
with Portland cement and various kinds of aggregates as 
given by Mr. Grant. The tests were made with 6-inch 
cubes. One-half were compressed by heating the con¬ 
crete into the mould with a mallet; the other half were 


HOW TO USE THEM 


303 


not compressed. The whole were kept in the air for a 
year before being crushed. 

The granite and slag might have been expected to 
have given the better results. It is probable that they 
were unwashed, and contained a considerable amount of 
dust. If the compression was done by hydraulic power, 
so as to obtain a uniform compression in all the cubes, 
the results would be more reliable. 


Crushing Strength (in Tons per Square Foot) of 
Portland Cement Concretes Having Various 
Aggregates. 


Nature of Ag¬ 
gregate. 

Six to One. 

Eight to One. 

Ten to One. 

Com¬ 

pressed. 

Not 

Com¬ 

pressed. 

Com¬ 

pressed. 

Not 

Com¬ 

pressed. 

Com¬ 

pressed. 

Not 

Com¬ 

pressed. 

Ballast. 

81.6 

72.8 

54. 

50. 

42. 

32. 

Portland stone 

162.4 

120. 

132. 

98. 

88. 

76. 

Granite. 

122. 

98. 

78.4 

58. 

62. 

46. 

Pottery. 

115.2 

98.4 

88. 

72. 

74. 

56. 

Slag. 

92. 

80. 

78. 

56. 

42. 

34. 

Flints. 

82. 

62. 

70. 

56. 

60. 

51.2 


Water for Concrete .—Water for concrete should be 
perfectly clean, and free from organic and inorganic 
impurities. As regards the quantity, it can only be 
said that for such purposes as the foundations for pav¬ 
ing, casting blocks, &c., or where the material can be 
well rammed, so as to insure perfect consolidation, less is 
required than where the concrete can only be poured or 
laid in position. When mixed with sufficient water, the 
concrete occupies about one-eighth more space than when 




















304 


CEMENTS AND CONCRETES 


mixed with the full quantity, and percolation through 
the former gauge would be greater than through the lat¬ 
ter. Yet by thorough ramming the former would oc¬ 
cupy less space and offer greater resistance to moisture. 
An over-watered gauge is slow to set, difficult to work, 
liable to surface cracks, and often there is a loss of 
strength, caused by escape of a portion of liquid cement. 
The work will also be unequal in strength, owing to the 
liquid cement flowing to various or lower parts, leaving 
parts of the aggregate bare and weak. 

It must not be inferred from the foregoing remarks 
that water is entirely unnecessary or of little value for 
concrete. On the contrary, it is of the utmost value. 
The evil is in the abuse, not in the use. Portland ce¬ 
ment has a great affinity for moisture. For instance, if 
a sack of cement is left on or in a damp place, a part of 
the contents soon becomes set and extremely hard, which 
is a proof of its affinity, and that moisture alone will 
set cement without water, far less excess of water. Fresh 
cement requires more water than stale cement. Cement 
gauged with sea water sets more slowly than with fresh 
water. Sea water should not be used in concrete in¬ 
tended for paving stables, chemical tanks, or similar 
places where it will come in contact with ammonia. Sea 
water having a lower freezing-point than fresh water, is 
sometimes used in frosty weather to allow the work to be 
carried on. It ought not, however, to be used for ex¬ 
ternal work, especially for plastering facade as it has 
the property of attracting moisture and causing an ef¬ 
florescence on the surface. Sometimes in frosty weather 
hot water, also hot lime, is used for concrete; but al¬ 
though these hasten the setting and hardening of cojv 
erete, they also wash away some of the finest and best 
particles of the cement during the gauging. A part of 


HOW TO USE THEM 


305 


the water also forms in little globules throughout the 
mass, and when the water-drops evaporate a series of 
small holes or bulbs are left, which deteriorate the 
strength of the concrete. Finally, it may be stated that 
the quantity of water required for gauging concrete is 
regulated by the class and condition of the aggregate, by 
the state of the atmosphere, and by the purpose for 
which the concrete is required. Another important point 
is the careful and thorough incorporation of all the ma¬ 
terials when gauging. A mass of raw materials, if 
gauged carelessly, will require more water to attain the 
same plasticity than that which is carefully gauged. Ap¬ 
proximate quantities of water are given for Portland 
cement plastering. For concrete the quantity is about 
21 gallons of water to 1 cubic yard of dry materials, or 
about 1 part by volume to 8 parts. It is a good maxim 
to bear in mind when mixing water for concrete, that 
other things being equal, the minimum is better than the 
maximum. Water may be said to give birth to the 
strength of cement; to carry the simile further, the ag¬ 
gregate may be termed the bone, the matrix the skin and 
sinew, and the water the blood of concrete. 

Gauging Concrete .—It is a common idea that concrete 
can be gauged and used anyhow, with any aggregate, or 
with any amount of water; and in consequence of a lax¬ 
ity in supervision in the selection of the materials, and 
their correct gauging and manipulation, unsatisfactory 
results are sometimes arrived at, the blame being at¬ 
tributed to the wrong cause. Gauging concrete re¬ 
quires considerable care to avoid waste of the materials 
and obtain the best possible work. Concrete can be 
gauged either by hand or by machinery. For small 
quantities, such as for stairs and similar work, the 
former is almost invariably used; and for large quan- 


306 


CEMENTS AND CONCRETES 


titles, such as for foundations or buildings, &c., the lat¬ 
ter, being more economical, is preferable. A careful 
and uniform method should be employed for hard 
gauging; nothing should be left to chance or rule of 
thumb. The gauge-board should be sufficiently large to 
allow the materials to be turned over without spilling, it 
should be placed as near the work as possible, and it 
should be cleaned after each gauge. 

For fine concrete, no more than 1 cubic yard should be 
gauged at a time. This is as much as three men can 
properly gauge at once and in the proper time—that is, 
before the “initial set” begins. Portland, cement con¬ 
crete, unlike some mortars, does not improve by pro¬ 
longed working. If larger quantities are desirable, then 
more men must be employed in the gauging. All ma¬ 
terials should be measured for each gauge, to ensure uni- 
form setting and strength, and also the best work. This, 
combined with the saving of time and materials, will re¬ 
pay a hundredfold the cost of the measures. It is a 
common yet a wrong way, when gauging for paving pur¬ 
poses, to measure the aggregate by so many barrowfuls 
to a sack of cement. Neither the aggregate nor the ce¬ 
ment can be accurately measured in this haphazard way. 
No man fills a barrow twice alike, and the cement being 
turned out of the sacks direct onto the aggregate is apt 
to vary, as it may contain lumps caused by damp, and 
very often some of the finest cement is retained in the 
sack, as more often than not it is simply drawn up and 
then thrown on one side without shaking it, as would be, 
cr at least should be done if the cement was emptied for 
air-shaking. The aggregate should be measured in a 
bottomless box or frame with handles at the ends, the 
cement in a box (with a bottom), and the water in a 
gallon metal measure or a pail made to contain 4 gal- 


HOW TO USE THEM 


307 


Ions. Five pailfuls of this size are about sufficient to 
gauge 1 cubic yard where the concrete can be well 
rammed or punned. For work that is simply laid, 1 gal¬ 
lon extra is required. The box frame is laid on the 
gauge-board and filled with aggregate (in a damp state). 
The frame is lifted off, and the aggregate spread over the 
board until about 6 or 7 inches thick. The cement is 
then distributed over the aggregate. The materials are 
then gauged by three men, two with shovels, and one 
with a rake or larry, the former facing the latter. The 
dry materials should be carefully but energetically 
turned over twice or even thrice, and then when being 
turned over the third time water must be gradually ad¬ 
ded by means of a rose fixed on a water-can. Water 
poured from a pail is apt to wash parts of the cement 
away; the water also cannot be regularly and gradually 
distributed over the dry materials as when a rose is 
used. The mass is again turned over twice or even 
thrice, until thoroughly incorporated. This turning over 
does not consist of merely turning the mass over in the 
centre or on one place of the board, but to be effectively 
done a shoveller should stand at each side of the board, 
and the raker at the end to which the mass is to be first 
turned; the shovellers lift the stuff and spread or rather 
scatter it on one end of the board with a jerking mo¬ 
tion, and the raker further mixes the stuff by working 
each shovelful backwards and forwards. This is repeat¬ 
ed, the stuff being turned to the other end of the board, 
after which it is turned to the center, the water being 
added as already described. The wet mass is then turned 
over twice in a similar manner, and finally finished in 
the centre of the board. The shovellers in the final mix¬ 
ing turn the stuff from the outside of the heap to the 
centre, while the raker gives the final touches. After 


308 


CEMENTS AND CONCRETES 


being gauged, it should not be disturbed, but immediate¬ 
ly shovelled into pails, and conveyed to the place of its 
use. The “initial set” begins nearly or as soon as gauged, 
and any after or unnecessary disturbance tends to de¬ 
stroy the setting properties of the cement. The practice 
of gauging, and afterwards regauging or knocking it up, 
is most objectionable, as it destroys its setting properties. 
No more should be gauged at one time than can be con¬ 
veniently laid in one operation. The gauging of this 
valuable material should not be left entirely to unskilled 
labor, but ought to be carried out under careful super¬ 
vision. 

Bamming Concrete .—-The ramming, beating, or pun¬ 
ning of concrete is of great importance. It compresses 
the concrete, rendering it more dense and free from 
voids, and forces out all superfluous water. The re¬ 
sultant gain in strength, durability, and imperviousness 
is by no means to be despised. Without compression it 
is impossible to obtain impervious concrete. Prolonged 
ramming, however, is dangerous, as it may be contin¬ 
ued until the cement is set, which would be a direct loss 
of strength. For this reason, the ramming of concrete 
made with quick-setting cement should immediately fol¬ 
low the deposition of the material, and be expeditiously 
done. The concrete should always be gauged rather 
stiff than soft. If in the latter form, the ramming will 
separate the more fluid portions, and produce strata of 
different densities. When the concrete is deposited in 
layers, the joints of each layer, if dry or exposed, should 
be well swept and watered before the next layer is de¬ 
posited. It is often advisable, especially in very dry 
work, to brush the joints with liquid cement after they 
have been swept and wetted. For larger constructional 
work, the joints should also be keyed by aid of a pick, or 


HOW TO USE THEM 


309 


by inserting stones at intervals into the concrete before 
it is set ? leaving them projecting 3 or 4 inches above the 
level of the joint. Another method of forming a key is 
effected by forcing a batten on edge about 2 or 3 inches 
deep into the concrete, at the middle of the joint, and 
when the concrete is firm or nearly set the batten is ex¬ 
tracted, thus leaving a groove which forms a key for the 
succeeding layer. 

No layer that has to be left for some time, or until 
dry, should be less than 4 inches deep. Thin layers are 
always a source of weakness. If the successive layers 
can be laid before the previous one is firm or set, the 
thickness is not of so much consequence. For large 
work, when each layer has to stand until set, the thick¬ 
ness may vary from 9 to 12 or even 18 inches. Ram¬ 
ming may be done by using an iron punner, or one made 
of hardwocd and bound with iron. Wooden mallets 
and punchers or iron hand-floats are most suitable for 
ramming stairs and cast work. The gain in strength 
is shown in the table of the crushing strength of Port¬ 
land cement concrete. 

Thickness of Concrete Paving .—The thickness of con¬ 
crete paving laid in situ as regulated according to the 
purpose and the position of the work. The thickness al¬ 
so depends upon the nature and solidity of the founda¬ 
tions. It is obvious that a thicker paving is required 
for a foundation that is weak or soft than for one that 
is strong and hard. The best foundations are those com¬ 
posed of strong and well-laid rough concrete. Founda¬ 
tions composed of broken bricks or stone thoroughly con¬ 
solidated by ramming are the next best. The thickness 
of foundations is also regulated by the nature of the 
soil and the subsequent traffic. Paving for the sidewalks 
of mam streets, or where the traffic is heavy and con- 


310 


CEMENTS AND CONCRETES 


tinuous, should not be less than 2 inches. For a medium 
traffic, and on a strong foundation, a thickness of 1^2 
inches will be sufficient. For side streets, garden paths, 
passages in houses, or similar places where the traffic is 
light and limited, a thickness from 1 to 1% inches will 
be ample if on a rough concrete foundation; but if on a 
dry ‘ ‘ dry, ’ ’ that is, broken brick or stone one 2 the thick¬ 
ness should not be less than iy 2 inches. The thickness 
for stable floors may vary from 3 to 4 inches, according 
to the class of horses. For instance, a thickness of 3 
inches would be ample for race or carriage horses, but 4 
inches is necessary for heavy cart horses. The same 
rule applies to yards, a thickness of 3 or 3% inches 
being sufficient for carriages, while 4 inches is required 
for carts, wagons, &c. Factory floors are generally made 
2 inches thick, but where there is machinery or wheel 
traffic a thickness from 2% to 3 inches is employed. By 
computing the volume and nature of the traffic, and 
comparing the tests of concrete paving given herein, the 
requisite thickness will be readily obtained. It must of 
necessity greatly depend on the class of the materials 
and manipulation used for the paving. Like most other 
articles, a good material will go further and last longer 
than a bad one. 

Concrete Paving .—Good pavements proclaim a city’s 
progress. Isodorus states that the Carthaginians were 
the first people to pave streets. The subject of paving 
and floors will be best understood by dividing it into two 
parts—namely, paving, which is a floor surface laid and 
resting on solid ground; and floors, by which are meant 
floors over voids. The following items briefly embody 
the processes used for most concrete pavings now in 
use. Paving in situ is either laid in “one coat” or 
“two coats,” the latter being in more general use than 


HOW TO USE THEM 


311 


the former, yet each method has its individual merits. 
One-coat work is not so liable to rise or laminate as two- 
coat work. It takes slightly less labor, the whole thick¬ 
ness being laid in one operation. The aggregate is 
either granite or slag, or both in equal proportions, 
gauged with Portland cement in the proportion of 2 of 
the latter to 5 of the former. Two-coat is laid with 
two different aggregates and gauges. The first coat has 
a cheap aggregate, such as ballast, clinkers, bricks, or 
wliinstone, broken so that they will pass through a 1 
inch mesh riddle, and gauged in the ratio of 1 of Port¬ 
land cement to 5 of the aggregate. It is laid till within 
1 inch of the finished surface. The second coat is laid 
as soon as the first is set, and is composed of 1 part of 
Portland to 2 of the aggregate, the latter being either 
crushed granite, slag, limestone, or whinstone that will 
pass through a 3-16 sieve. In some districts fine shingle 
is used for the topping aggregate. 

Quick-setting solutions are used to reduce the time re¬ 
quired to allow the paving to harden before it is avail¬ 
able for traffic. Many pavements are ruined by being 
used before having become sufficiently hard and set. 
Many of the so-called quick-setting materials have the 
desired effect of setting the concrete quickly, but the 
work in many cases is none the better for these solutions. 
On no account should these quick-setting materials be 
used, unless thoroughy tested and the concrete proved 
durable by use and time. In order to protect the sur¬ 
face and allow the paving to be used immediately, P. M. 
Bruner, an American engineer and concrete specialist, 
covers the surface of the pavement directly it is finished 
with a thin coat of plaster or Parian cement, which ad¬ 
mits of walking upon in a few hours, and resists pedes- 


312 


CEMENTS AND CONCRETES 


trian traffic until the surface proper is sufficiently hard, 
after which it is shelled off with a trowel. 

Eureka Paving .—This is the name for an improved 
concrete, which has been extensively used with good re¬ 
sults for many purposes, such as pavements, floors and 
stairs. Eureka, if not exactly one-coat work, is nearer 
that than two-coat work, and may be said to be the 
happy medium, or a combination of both. Eureka is 
laid in two layers. The first is termed the “rough 
coat,” and the second the “fine coat” or “topping.” 
The topping is laid nearly as scon as the rough coat is 
laid, just as in rendering or dubbing-out plaster work. 
The materials and gauges are nearly alike for both 
layers. The gauged rough stuff is laid on the founda¬ 
tion, previously wetted to prevent suction, and spread 
and beaten with an iron hand-float. The laying, spread¬ 
ing and beating is continued until the rough surface 
is within % inch of the finished line. The surface of 
the rough coat is made fair, and a uniform thickness 
for the topping is obtained by passing a “gauge-rule” 
across the surface. A uniform thickness of topping 
gives an equal expansion, therefore the surface is not 
liable to crack. The suction is also more regular, which 
permits of the trowelling to be done with greater free¬ 
dom, and without causing hard and soft places on the 
surface. 

As many alternate bays are laid as will allow of all 
being topped and finished the same day. When the 
number of bays to be laid in on one day has been de¬ 
cided, and the last one roughened in, the first bay will 
be firm to receive the topping. The topping is laid and 
spread with a wooden hand-float, ruled and trowelled 
and brushed as afterwards described in the general pro 
cess. This method of laying a part of the thickness of 


HOW TO USE THEM 


313 


the paving, gauging stiff and beating the mass, forces 
it into the interstices of the broken dry foundation, and 
not only consolidates the foundation and the rough coat, 
but also forms a solid bed to receive the topping. The 
topping goes in sooner and more regularly on a stiff- 
gauged and well-beaten coat than on a soft-gauged one, 
or than if the whole thickness of the paving were laid 
in one coat. 

Eureka Aggregate .—The method of preparing the ag¬ 
gregate for Eureka is of the utmost importance. The 
labor expended on its preparation is more than repaid, 
not only in the ease and rapidity when finishing, but also 
in the satisfaction of doing a strong and workmanlike 
job. Slag and granite is far more preferable to gravel 
or stone as an aggregate. Slag and granite in equal 
proportions have been used with good results. The size 
ordered from the furnace or quarry should be % inch 
screenings. It must be washed through a % inch sieve 
in a tub or iron tank. The coarse part rejected by the 
sieve to be laid aside for the rough coat. The fine ag¬ 
gregate is then washed again through a fine sieve to ex¬ 
tract any mud or impalpable powder, as the presence of 
such impurities weakens the consolidating power of the 
cement, and decreases the ultimate strength of the con¬ 
crete. This fine aggregate for the topping should be 
angular and of various graduating sizes, from that of 
fine sharp sand to the largest size that has passed through 
the Ys inch sieve. It has been proved by experience and 
the test of time that an artificial stone made with a fine 
aggregate has not only more resemblance to the grain or 
texture of natural stone, but is also denser, and wears 
better and with more uniformity, than one made with a 
large, round, or equal-sized aggregate. The use of small 
and angular aggregate of the graduating sizes ensures 


314 


CEMENTS AND CONCRETES 


their fitting closer and interlocking together, thus form¬ 
ing a stronger bond, giving a regular key and freedom 
for each separate piece to be coated with cement, the 
whole forming a solid and homogeneous body with a 
hard surface. Concrete with large or round aggregate, 
and the various pieces disproportionate in size to each 
other, will fit loosely and unevenly, and only touch at 
their most prominent points, thus leaving voids, and con¬ 
sequently unsound work. The voids may perchance be 
wholly or partly filled with matrix, still this is an un¬ 
necessary waste of cement. Consequently, concrete pav¬ 
ing having large or round aggregate wears unevenly, and 
leaves the large or round pieces uncoated and loose, or 
so exposed above the surface that they soon get dis¬ 
lodged, leaving a series of small holes, which sooner or 
later wear larger and larger. Another point of import¬ 
ance is that concrete with a fine hard aggregate is more 
plastic, works freer, and has a greater compressive 
strength than concrete with a large or soft aggregate. 
Eureka concrete, having a fine, clean, and regulated ag¬ 
gregate, should be used for the topping of paving, steps, 
landings, or for any class of work exposed to friction or 
wear. It is well to remember that a good matrix will 
not make a bad aggregate strong, although a bad ag¬ 
gregate will make a good matrix weak, or rather the re¬ 
sultant concrete weak. 

Eureka Quantities .—The quantities for the rough 
coat are 1 part of Portland cement and 4 parts of the 
coarse portion of Eureka aggregate. These materials 
must be gauged stiff, only as much water being used as 
will allow the mass to be thoroughly mixed and plastic. 
The quantities for the topping are 2 parts of Portland 
cement to 5 of the fine aggregate, and gauged about the 
consistency of well-tempered “coarse stuff,” as used for 


HOW TO USE THEM 


315 


floating. Experiments prove that neat cement is infe¬ 
rior in wear-resisting qualities (such as frictional wear 
and pedestrian traffic) to mixture of cement with sand 
or other aggregate, being in fact equal to a mixture of 
about 1 part of cement to 3 parts of aggregate. The 
best wearing qualities are obtained by a mixture of 2 
parts of cement to 3 of aggregate. 

Levels and Falls .—Accurate levelling and adjustment 
of the requisite falls are important features for pave¬ 
ments and flooring. Levelling is the art by which the rel¬ 
ative heights of any number of points are determined. 
Falls are used to allow rain and water used for cleansing 
purposes to run off into channels and drains. The levels 
and falls in good buildings are generally marked, on the 
drawings, but it is imperative that the worker should be 
conversant with the necessary amount of falls for paving 
purposes, as many unforeseen difficulties often arise in 
this class of work, especially in large surfaces. The most 
accurate and speedy way of setting out levels and falls 
is of special service to concrete paviors. The importance 
of these features will be readily appreciated, especially 
where these paving preliminaries are left to the care of 
the concrete layers. The amount of cross fall for street 
pavements varies according to the class and position of 
the work. The fall is also regulated by the gradient. For 
a level stretch of paving it is generally 1 to 60, therefore 
for a pavement 6 feet wide it would be 1 inch. The fall 
for rising ground is usually % inch for every 2 feet in 
the width of the pavement. The falls for stables and 
yards are given under their respective headings. The 
points for levelling—also for falls—are formed by driv¬ 
ing wooden pegs into the ground at the most suitable 
points. The heads of the pegs represent the finished face 
of the pavement. They are made level with each other 


316 


CEMENTS AND CONCRETES 


by the aid of a parallel rule and a spirit-level. Inter¬ 
mediate pegs may also be levelled by means of boning 
rods. 

Pavement Foundations —Good foundations for con¬ 
crete paving are of primary importance, and unless the 
bottom is firm, and the foundation is sound, the best 
made and laid concrete will subside, crack, and be per¬ 
manently spoilt. Pavements generally cover a large 
area, and the superstructure, however strong, must have 
a firm foundation. Foundations consist of two parts— 
the first is the bottom ground or natural foundation; the 
second is the made-up or artificial foundation; but for 
simplicity the first is termed the “bottom,” and the lat¬ 
ter the “foundation.” The latter may be “dry” or 
“gauged.” If the bottom is soft, it must be well ram¬ 
med before laying the dry materials for the foundation, 
or a layer of common coarse (concrete for gauged work. 
When excavating the ground to receive the foundation, 
the depth from the intended finished surface of the 
pavement should be about 5 inches for paving 2 inches 
thick, 6 inches deep for paving 2% inches thick, and 7 
inches deep for paving 3 inches thick. The above depths 
are for dry foundations, and where the traffic is light, 
such as side-walks, playgrounds, and passages. If the 
bottom is soft, or the paving intended for heavy traffic, 
the depths may be increased, and the bottom well ram¬ 
med before the materials are laid. The materials for the 
dry foundations are broken bricks, stone rubble, or other 
hard core. They should be spread on the bottom, and 
broken in situ. The breaking in situ tends to consoli¬ 
date the bottom and the foundation. When broken, no 
piece should be left that will not pass through a 2% inch 
ring. If the paving is intended for heavy traffic (carts 


HOW TO USE THEM 


317 


or the rolling of heavy casks) it is best to have a rough 
concrete foundation. The rough concrete should be 
from 4 to 7 inches deep, according to the firmness of the 
bottom and class of traffic. This concrete is composed 
of ballast or equal parts ballast and broken bricks, coke- 
breeze, or hard clinkers, gauged in the proportion of 1 
of Portland cement to 5 or 6 of aggregate. It should be 
laid to the desired fall. If lime instead of Portland ce¬ 
ment is used for the rough concrete, great care should 
be taken to thoroughly damp the surface, and allow a 
sufficient time for the lime to expand and any lumps of 
unslaked lime to slake, before the fine concrete is laid. No 
paving should be laid until the rough concrete is thor¬ 
oughly set. Allowance must also be made for any set¬ 
tlement of the bottom, and for any subsidence, contrac¬ 
tion, or expansion of the concrete foundation. The 
* rough is not so liable to contraction or expansion as fine 
concrete, but it is more liable to subsidence. Expansion 
is due to the cement not to the aggregate • and as there is 
less cement in rough concrete than in fine, it has less 
power of expansion, and owing to the greater amount 
and weight of aggregate, there is the lesser power of con¬ 
traction. The size of aggregate for rough concrete is 
also larger than for fine; consequently each piece offers 
a greater resistance to the cement. Subsidence is due to 
the settlement by gravitation of the aggregate to the bot¬ 
tom, which takes place after the excess water, or even 
the liquid cement, has percolated through voids or spaces 
of badly made or laid concrete. Unequal subsidence is 
caused by bad and unequal gauging; one gauge being 
firm, keeps in position; while if soft and sloppy, the ex¬ 
cess water either settles in the deepest places, or escapes 


318 


CEMENTS AND CONCRETES 


into the ground, thus allowing the body of the concrete 
at those parts to subside. 

Screeds and Sections .—Screeds are used as guides and 
bearings for leveling and ruling off. They are general¬ 
ly formed with wood rules, planed on all sides, and in 
suitable sizes, and are termed “screed rules.’’ Screeds 
are sometimes formed with the same kind of material as 
used for the pavement, and are termed ‘ 1 gauged screeds. ’ ’ 
Screed rules give the best results; they are speedily laid; 
can be used at once, and form a clean and square joint 
when laying work in sections. Screed rules are tempo¬ 
rarily fixed on the foundation by laying them on narrow 
strips of gauged concrete, and then made straight, and to 
the proper falls, by laying the edge of a straight-edge on 
them, and tapping with a hammer till firm and true. 
When the bay is finished and set, the screeds are re¬ 
moved by gently tapping with a hammer, leaving a clean, 
straight, and square joint. Where there is only a small 
quantity of screeds required, or where time will not per¬ 
mit of waiting for the concrete bedding strips to set, the 
screed rules can be fixed on gauged plaster, which al¬ 
lows the screeds to be used at once. The plaster should 
be cleaned off at the side intended to be laid, to ensure a 
sound bed for the concrete, and a square joint. Gauged 
screeds may be also formed with gauged coarse plaster. 
They are best done as described for “pressed screeds.” 
In laying large surfaces it is best to arrange the screeds, 
so that the work can be laid in alternate sections or bays, 
which will afford greater facility to get at the work, and 
also to allow the isolated bays to expand. For instance, 
if laying a stretch of paving 50 feet long and 6 feet wide, 
this would be laid out in 5-feet bays, the screed rules, 
each 6 feet long, being laid so as to form the odd num- 


HOW TO USE THEM 


319 


bered bays to be laid and finished first. This allows the 
workmen more freedom by standing on the empty bays 
when finishing the laid bay. The screeds are then re¬ 
moved, and the intermediate bays laid, the sides of the 
finished bays serving as screed or bearing when ruling 
in. Boards or bags are laid on the finished bays to pro¬ 
tect the surface, and give a footing for a workman to 
finish off the intermediate spaces. It must not be for¬ 
gotten to fix the screed rules toward the curbs, also to 
keep the ends of the screed about % inch about the curb, 
to allow for any subsidence, and for the water to run 
off. This also provides for the greater amount of wear 



Sections of Concrete Kerb, Channel, and 
Paving, 
no. 1. 


that takes place near to than actually on the curb. The 
foundations should be thoroughly saturated with water 
before the screeds are fixed. If this is not done, the 
brick or other dry material used will absorb the moisture 
or life from the concrete, and render it dry or dead. The 
drenching with water also frees the broken materials 
from the dust caused by breaking the large pieces in 
situ. In laying paving or a gauged foundation, the sur¬ 
face should be well swept with a hard broom and after- 









320 


CEMENTS AND CONCRETES 


wards damped, so as to ensure the perfect cohesion and 
solidity of the foundation and the paving. The curbs 
and channels are sometimes made in situ, but more often 
they are cast and laid in the same manner as ordinary 
stone. Cast work is harder than laid work; it also al¬ 
lows the paving to be laid with greater freedom. Illus¬ 
tration No. 1 shows sections of the street curbing and 
channel which may be used in connection with slab pav¬ 
ing, or pavements laid in situ. 

Laying Concrete Pavements .—The foundations having 
been damped, and the rough stuff gauged, it is carried 
in pails and emptied at the top end of the bay. The plas¬ 
terer spreads it with a layer float, and rams it well into 
the foundation. When he has laid a stretch the whole 
width of the bay, and as far as he can conveniently reach, 
he moves back and lays the remaining portions of the 
bay in the same way until complete. The rough stuff 
surface is then made fair, but not smooth, with the gauge 
rule. The remainder of the bays are dealt with in rota¬ 
tion. The fine aggregate is then gauged, and laid and 
spread until flush with the screeds. The stuff should be 
rather above than below the screeds, to allow for subsi¬ 
dence by subsequent ramming, ruling and patting. All 
concrete bodies over 2 inches thick should be deposited 
in layers. Each layer should be well rammed with an 
iron, or hardwood temp, bound with iron. Concrete 
gains strength by compression, and consequently its 
density, imperviousness, and durability are increased. 
Even for 2 inch pavement better results are obtained if 
the stuff is deposited in two layers, each layer well 
beaten with an iron hand-float. If only 1 y 2 inches thick, 
it should be consolidated by being beaten with an iron 
float. The surface is next ruled with a floating rule. 


HOW TO USE THEM 


321 


The rule is worked square or edge, and the concrete cut 
and beaten in successive short and quick strokes. If the 
stuff is soft and laid too full, the rule is worked loosely 
on edge with a zigzag motion, so as to draw the excess 
stuff and water off the surface, and leave the body full 
and regular. If there are any hollow places, they are 
filled up with stuff, and the rule again applied. In all 
cases the surface should be finally straightened by beat¬ 
ing with the rule. This process leaves the surface more 
uniform, straight, and solid than by dragging or working 
the rule. 

Trowelling Concrete .—After being ruled, and when 
slightly firm, the surface is beaten with a wood hand- 
float, which lays any irregular parts or projecting pieces 
of aggregate. The beating or patting is continued until 
the “fat” appears on the surface. It is then trowelled, 
or rather ironed, the trowel being worked on the flat of 
the blade with a circular motion. The plasterer, when 
trowelling off, should have a hand-float in the other 
hand to lean on when reaching to a far off part. The 
float is also useful to pat any dry parts. The surface 
must be finished with a semi-dry stock-brush to obtain a 
uniform grain. A vast amount of care is required in 
trowelling off. Perfection can only be attained by prac¬ 
tice, and a close observation of the materials, conditions, 
and the state of the atmosphere during the progress of 
the work. The best effects can only be attained by 
acquiring a knack of working the trowel on the flat, and 
by knowing when to begin and when to leave off. It is a 
waste of time, and the cause of an unequal surface, if 
the trowelling is begun before the stuff is firm; but time 
and labor will also be lost if the trowelling is left until 
the stuff is too stiff, or has nearly set, for then the sur- 


CEMENTS AND CONCRETES 


;*22 

face will be rough and patchy. In either instance the 
surface is more or less spoilt, and the ultimate appear¬ 
ance and hardness seriously affected. 

Grouting .—The use of neat cement for trowelling off 
should not be resorted to (this is termed “grouting”), 
and is used when the surface is left till set, or when it 
has not been properly patted and trowelled. The. ex¬ 
pansion of a strong and weak gauge being unequal, the 
result is that the surface peels, or should it adhere, it is 
patchy and discolored. Where grouting is unavoidable, 
the cement should be gauged with an equal part of fine 
aggregate, the aggregate being the same as used for the 
topping. 

Dusting .—Another bad process is that of sprinkling 
dry .neat cement over a soft surface (this is termed 
“dusting”), and is used to absorb the moisture caused 
by sloppy gauging. It has drawbacks similar to grout¬ 
ing. If unavoidable, the cement should be mixed with 
fine dry aggregate in the same proportion as the topping. 
If the stuff were trowelled at the correct time, there 
would be no necessity for grouting; and if properly 
gauged, no need for dusting. No concrete surface can be 
made so solid and hard as when it is finished in one body 
and at one time. 

Temperature .—It is well known that extreme heat and 
cold effect the expansion and contraction of iron. These 
extremes have a similar effect on concrete, especially dur¬ 
ing the process of setting and hardening. Equality of 
temperature during setting is desirable. Cold and 
humid atmosphere retard setting; hot humidity acceler¬ 
ates it. Concrete laid in cold weather stands better 
than that laid during hot. Concrete laid in mild damp 
weather is better than in either extreme. During high 


HOW TO USE THEM 


323 


temperatures, the surface, when sufficiently hard, should 
be covered with damp deal saw-dust, old sacks, mats, or 
sail-cloth, and saturated at intervals with water. If the 
sun’s rays are hot, the surface of the work while in 
progress should be protected by extending tarpaulin or 
sail-cloths above the parts being laid. Concrete surfaces 
are further hardened by flooding with water, or where 
this is not practical, covering with wet saw-dust or sand 
as soon as set. Care must be taken that the saw-dust is 
clean and of a light color, as otherwise it will stain the 
work. 

Non-Slippery Pavements .—Concrete pavements for 
special purposes are rendered non-slippery by mixing y 8 
inch lead cubes with the topping stuff. Lead cubes about 
y 2 inch square laid by hand from 1 inch to 4 inches 
apart in the moist concrete surface, have been used for 
rendering concrete surfaces non-slippery. Iron and 
brass filings are also used for the same purpose, and also 
for increasing the wear-resisting of concrete surface. 
Roughened, indented, grooved, and matted surfaces are 
also used to obtain a better foot-hold on concrete sur¬ 
faces. 

Grooved and Roughened Surfaces. —Stables, yards, 
&c., are grooved and channeled on the surfaces to pre¬ 
vent animals from slipping, and also to carry off urine 
or other liquids to the traps or gulleys. Indented sur¬ 
faces are useful on steep gradient to give a better foot¬ 
hold. Grooves are made with a special wood or iron 
tool, which is beaten into the surface as soon as the con¬ 
crete is floated. The grooves for stables are generally 
made about 5 inches from centre to centre, and the depth 
about % inch. A line is first made at the one end of the 
work, and the groover is then laid on this line, and beat- 


324 


CEMENTS AND CONCRETES 


en down with a hammer to the desired depth. Before it 
is taken off, a parallel rule is laid on the surface and 
against the groover, which is then taken up and laid 
close to the other side of the parallel rule, and beaten 
in as before, and so on until the whole surface is done. 
The width of the parallel rule is equal to the desired 
width between the grooves, less the width of the groover. 
Grooves, however long, can be made by moving the tool 
along, and against a long parallel rule. After stretch of 
grooves have been sunk, the surface is trowelled, and the 
indentations made true. It may be necessary to apply 
the groover again, and beat or work it forward and back¬ 
ward and further regulate their depth and straightness. 
They are then made smooth with a gauging trowel and 
finished with a damp brush, the sides of the grooves being 
left smooth to give a free passage for liquids. 

Grooves on a surface having a fall should radiate to¬ 
ward the deepest point. A level surface may be made 
to carry off the water by the indentation being formed 
wider and deeper towards the outlet. Street and other 
pavements are sometimes indented with metal rollers to 
give a better foot-hold. Platforms and other surfaces are 
sometimes made rough or indented by beating the moist 
concrete, with a “stamping-float.” The sole has a series 
of squares projecting about % inch, each square about 
1 inch, and a half inch apart. Concrete surfaces are al¬ 
so roughened or matted by dabbing the surface as soon 
as trowelled with a coarse stiff whale-bone brush. Illus¬ 
tration No. 2 shows three designs of grooved surfaces for 
carriage drives, conservatories, &c. A plain border, or 
one with a single width of the main design, is generally 
formed on the sides and ends of the floor. A rough mat- 


HOW TO USE THEM 


325 


ted surface may also be obtained by pressing or beating 
a wet coarse sack or matting over the moist concrete. 

Stamped Concrete .—Various materials and methods 
are used for stamping or indenting concrete surfaces to 
obtain a better foot-hold, or to form any desired pattern. 
Iron stamps are generally used, but owing to their 
weight and rigid nature, are unsuitable for large sec- 


Fig. I. Fig. 2. Fig. 3. 



Three Examples of Grooved Surfaces. 

NO. 2. 

tions. Plaster stamps are sometimes used for temporary 
purposes, or for small sections and quantities. Stamps 
for large concrete surfaces should be composed of a ma¬ 
terial that is easily made to the desired form durable 
and slightly flexible. 

Expansion Joints .—Compressive or flexible joints are 
used to allow for any expansion or contraction that may 
take place in a large area of concrete exposed to atmos¬ 
pheric changes. There are various methods in use for 


























326 


CEMENTS AND CONCRETES 


the purpose. The first is to set out the area in small 
sections, and to lay them in alternate or isolated bays, 
thus giving time for their expansion before the inter¬ 
mediate bays are laid. This method, by dividing the 
area into small sections, is the best for preventing cracks, 
because small sections are stronger than large ones; and 
in the event of any subsidence in the foundation, the 
surface fissures are limited to the immediate joints of 
the section. Contraction and expansion is also less, in 
small bodies than in larger ones. 

Another method of forming joints is by cutting with a 
wide chisel or a cutting tool before the rough concrete is 
set, a corresponding joint being cut in the fine concrete 
topping. False joints are made by indenting the top¬ 
ping after it is trowelled. A metal roller is used for 
finishing true joints and forming false joints. Frame 
strong enough to resist the expansion of the concrete 
would not only increase the density and strength of 
concrete paving and blocks, but also effectually prevent 
its cracking. 

Another method for forming sections in large sur¬ 
faces of pavement of floors to prevent cracks is effected 
thus:—first set out the size of proposed sections on the 
rough or first coat, then with a straight-edge, a wide 
chisel, or a cutting tool and a hammer, cut through the 
rough coat, so as to divide it into sections as set out. 
This done, insert wood strips into the cutting, keeping 
their top edges about % inch below the screeds or rules 
which represent the finished surface. The* strips are 
made from % to 1 % inches wide, 3-16 inch thick, and in 
suitable lengths. The width is regulated according to 
the thickness of the paving. For instance, for two inch 
paving the widths should be 1 % inches. This allows 


HOW TO USE THEM 


327 


about % inches in the rough coat (with % inch play 
from the bottom), and about % inch in the topping, and 
y 8 inch for the upper thickness of the topping to cover 
the top edges of the strips. After the strips are inserted 
the rough coat is beaten up or made good to the sides of 
the strips, and then the topping is laid and trowelled in 
the usual way. The surface joints are then made direct- 



-Half Plan of Coach Yard, with 
Section through Centre. 


NO. 3. 

ly over the strips, with the aid of a straight edge, so as 
to form a clean and sharp joint. As already mentioned, 
these strips allow for any subsequent contraction or ex¬ 
pansion, thus avoiding zigzag cracks ; and in the event of 
repairs to underneath pipes, each section can be cut out 
and relaid separately without injury to the adjoining 
sections. This process of inserting strips in the rough 
coat, cutting nearly through the topping, gives the same 
results as if the strips were laid flush with the surface 
of the topping, with the advantages that the surface can 
be more readily trowelled, and is more pleasing to the 

















328 


CEMENTS AND CONCRETES 


eye, because the strips are not seen. A cutting tool is a 
blade of steel about 5 or 6 inches long and 4 inches wide, 
with a wood handle at one end. The section of the blade 
is well tapered, so as to obtain a sharp cutting edge, and 
form a wide top edge to offer a broad surface for the 
hammer while being beaten. 

Washing Yards .*—Eureka concrete being of a hard 
nature, and having a close and smooth surface, is well 
adapted as a flooring for all washing or cleaning pur¬ 
poses. The surface being smooth, it can in turn be read¬ 
ily cleaned. Illustration No. 3 shows the half plan of 
washing yard for washing carriages, &c. 

Stable Pavements .—The paving for stables, and other 
places for keeping animals, should be jointless, non-ab¬ 
sorbent, hard, and durable. Such paving must not be 
slippery, yet smooth enough to be easily washed, the 
whole laid to falls, and grooved to give an easy and 
ready passage for liquid manure and water when being 
washed. No material can so fully meet these require¬ 
ments as a well-made and well-laid concrete. Granite 
sets are hard, but slippery. Bricks are too absorbent; 
the urine percolates between the joints and generates 
ammonia and other effluvia which are detrimental to the 
health of the animals. (See Nos. 4 and 5.) 

Stables are generally laid with a fall toward the main 
channel. The amount of fall varies according to ideas 
of the horse owners. The fall adopted by the War office is 
1 in 80 from the top of the manger to the main channel, 
and 1 to 36 from each side of the stall to the centre groove. 
The width of the main channels is usually set out with 
screed rules, which also act as screeds to work from. 
Channels are generally formed after the other surface is 
finished. Sometimes templates are fixed on the bed of 


HOW TO USE THEM 


329 


the channels, and the space filled in and ruled off with a 
straight-edge while the whole surface is being formed. 
The thickness of stable paving varies from 2 to 3% 
inches, according to the class of horse. The thickness of 
the stalls is often decreased toward the manger. 

The most useful length is 2 feet 6 inches. They can 
be cut with a chisel as easy as cutting stone. Special 
slabs can be made for circular work, also with rebated 
sinking for metal plates, to cover coal-holes, drains, gas 
and water taps, &c. Concrete paving slabs are laid in 
precisely the same way as natural stone. 



Section, of Channel, at 3 



-Sections of the various Parts of the Stable Floors 
shown on Illustration 


no. 4. 


NO. 5. 


Concrete Slab Moulds .—Slab moulds are made with 
iy 2 inch boards lodged together. On this ground, wood 
sides and ends (each being 2% inches by 2 inches, or 3 
inches by 3 inches, according to the desired thickness of 
slab) are fixed. One side and end is held in position 
with thumb screws, which fit into iron sockets, so that 
they can be unscrewed to relieve the slab when set. The 
bottom and the sides and ends are lined with strong iron 
or zinc plates. 








330 


CEMENTS AND CONCRETES 


Slab Making .—Slabs are mostly made by machinery. 
The materials are 1 part of Portland cement mixed dry 
with 2 y 2 parts of crushed granite and slag in equal pro¬ 
portions that have been washed and passed through a hi 
inch sieve. They are thoroughly incorporated together 
in a horizontal cylinder worked by machinery, a mini¬ 
mum of water being added, and the mixing continued 
until the mass is well gauged. The mould, which has 
been previously oiled, is placed on a shaking machine 
known as a “ trembler ’ 9 or “ dither, ’ ’ which gives a rapid 
vertical jolting motion to the mould and its contents. A 
small portion of “slip,” that is, neat cement, is laid 
round the angles. The machine is then started, and the 
concrete laid on the mould by small shovelfuls at a time, 
a man with a trowel spreading it over the mould until 
full. The surface is then ruled off. If both sides of the 
slabs are required for use, the upper surface is trowelled. 
The whole operation of mixing, filling in, and ruling off 
takes about seven minutes. The filled moulds are re¬ 
moved and allowed to stand for about three days. The 
slabs are then taken out, and stacked on edge and air- 
dried for about five days. They are then immersed in 
a silicate bath for about seven days, and are afterwards 
taken out and stacked in the open air until it is required 
for use. They should not be used until three months 
old. Paving slabs are also made by hand, by ramming 
and beating the moist concrete into the mould with an 
iron hand-float. Powerful ramming, trituration, or vio¬ 
lent agitation of the gauged material in the mould, tend 
to consolidate concrete, and it is possible to further in¬ 
crease homogeneity by the use of hydraulic pressure. 

Induration Concrete Slabs .—The surface of concrete 
slabs or other work exposed to friction or wear* may be 


HOW TO USB THEM 331 

hardened by soaking in a silicate solution. Silicate of 
soda has a great affinity for the materials of which con¬ 
crete is composed, and by induration causes the surface 
to become hard, dense, and non-porous. 

The silicate of soda and potash is known as soluble 
glass or dissolved flint. The soluble silicate is a clear 
viscous substance made from pure flint and caustic soda, 
which is digested by heat under pressure indigester. Its 
strength is technically known as 140 degrees, which 
shows 1,700 on a hygrometer. When used as a bath for 
concrete, it is diluted with water, the proportion vary¬ 
ing from 6 to 10 parts of water to one of silicate. Con¬ 
crete pavements, laid in situ, may also be hardened by 
washing with silicate solution. They should not be sili- 
cated until two days after being laid, to allow the mois¬ 
ture to evaporate and the silicate to penetrate. 

Mosaic .—The art of making mosaic is at the present 
time scarcely within the province of plasterers, but in 
former times many kinds were made in situ or in slabs 
by plasterers. The subdivision of labor has to a great 
extent caused mosaic-making to be confined to special¬ 
ists. Concrete is still made by plasterers. A brief de¬ 
scription of this and other kinds may prove useful as 
well as interesting, especially to plasterers who are in 
the habit of fixing tiles and working in concrete. Mosaic 
is the art of producing geometrical, floral, or figured de¬ 
signs, by the joining together of hard stones, marbles, 
earthenware, glass, or artificial stone, either naturally 
or artificially colored. The term “mosaic” embraces a 
wide range of artistic processes and materials for the 
decoration of floors, walls, ceilings. The Egyptians were 
experts in mosaic. The Cairo worker as a rule had no 
drawings made beforehand, but the mosaic design was 


332 


CEMENTS AND CONCRETES 


constructed by the artist as he arranged the pieces on 
the ground. The mosaic pavements of Cairo are of a 
slightly different character from those used for wall 
decoration, and are generally composed entirely of mar¬ 
ble tesserae (and sometimes red earthenware) of larger 
size than the delicate pieces included in wall mosaics. 
They are arranged to form geometrical patterns within 
a space of about two feet square. Each square slab is 
made separately, and the pieces are set, not in plaster, 
but in a composition of lime and clay impervious to 
water. The clay must be unbumt, just as it comes from 
the pit. Saracenic mosaic in Egypt is a combination of 
the tesselated method with a large proportion of sectile 
mosaic. The Romans also were great workers in mosaic. 
The mosaics of Byzantium and Ravenna consisted of 
cubes of opaque and colored glass. 

The general method used here for pavement mosaic is 
as follows: The repeated design is traced on stout paper 
and small pieces of marble, or more often tile, are 
gummed on the paper, following the design of form and 
color, one piece at a time (with the smooth face down¬ 
wards) being laid until the design is completed. The 
mosaic slabs, which are thus temporarily kept in posi¬ 
tion, are sent to the building and laid where intended. 
A rough concrete foundation, which has previously been 
made level, is then floated with Portland or Keen’s 
cement, and the slabs with paper are then damped and 
drawn off, and any openings or defects filled up with 
small pieces of the same form and color as the design. 
The slabs are made in various sizes according to the de¬ 
sign. For instance, a border 12 inches wide may be made 
from 3 to 6 inches long. When laying the slabs, it is best 
to begin at the centre and work outwards, and any ex- 


HOW TO USE THEM 


333 


cess or deficiency taken off or made up in the plain part 
of the border at the walls. The tiles are made at pottery 
works in the required sizes and colors. The thickness is 
generally about % inch and the average surface size 
about % inch. Females are often employed fixing the 
pieces on the paper. The designs of coats of arms, mono¬ 
grams, dates, figures, flowers, and foliage are effectively 
produced by this simple and cheap process. 

Concrete Mosaic .—All mosaics are more or less of a 
concretive nature, and the trade term of “concrete mo¬ 
saic” is due to the fact that the matrix used is Portland 
or other cement gauged with the marble aggregate, and 
laid in most cases in a similar manner as ordinary con¬ 
crete. Concrete mosaic is extensively used for paving 
halls, corridors, conservatories, terraces, &c. It is also 
used for constructing steps, landings, baths, pedestals, 
&c. Slabs and tiles made of this class of mosaic for 
paving purposes are slowly but surely proving a for¬ 
midable rival to Italian mosaic encaustic tiles. It can 
be made in larger sections, thus facilitating rapidity of 
laying. It is more accurate in form, durable, non-slip- 
pery, and cheaper. The last reason alone is a favorable 
item in this keen age of competition. Where marble has 
been scarce, broken tiles, pottery, colored glass, flints, 
white spar, &c., have been used as aggregate. If the 
marble chips are obtainable as a waste, and near the place 
of manufacture, the primary cost is small. If the moulds 
are of metal, and made in sections so as to form a series 
of moulds in one case, and the casts are pressed by means 
of a hydraulic power, the cost of production is reduced 
to a minimum. If the casts are polished in large num¬ 
bers by machinery on a revolving table, the total cost is 
further reduced. For local purposes they can be made 


334 


CEMENTS AND CONCRETES 


by hand at a medium cost. Slabs are made in almost 
any size, but generally from 4 to 6 feet superficial. The 
thickness varies from 1 to 1% inches. Tiles are usually 
made about 10 inches square and 1 inch thick. The tiles 
are generally made with a face of cement and white mar¬ 
ble, or white and black marble chippings. They are 
backed up with a cheaper aggregate. Various tints of 
the face matrix are obtained by mixing the cement with 
metallic ovides. The tiles are made in wood or metal 
moulds, with metal strips to form the divisions of form 
and color in the design. If the design is fret pattern, 
the gauged material is put in between the strips that 
form the band of the fret. When the stuff is nearly set, 
the strips are taken out, and the other part filled in with 
another color. Sometimes the band or running designs 
are cast in a separate mould, and when set placed in posi¬ 
tion in a larger mould, and the ground filled in, cover¬ 
ing and binding the whole in one tile. Another plan is 
to lay a thin coat of cement on the face of the mould, 
forming the design with small marble chips by hand, by 
pressing the marble into the cement as desired. When 
it is firm, it is backed up with the ordinary stuff, and 
when set, they are ground and polished. 

Concrete Mosaic Laid “in Situ .”—Pavements for 
halls, passages, shops, landings, &c., are also done in situ. 
A rough concrete foundation is first laid fair to falls 
and levels within y 2 inch of the finished surface line. 
This y 2 inch space is to receive the plastic marble mo¬ 
saic. The main or centre part is generally done first 
and the border last. This allows a walking space or 
bearing for boards, laid from side to side to work on 
when laying the centre. A plank sufficiently strong to 
keep one or two crossboards from touching the work is 


HOW TO USE THEM 


335 


laid along each side. On the side planks the crossboards 
are laid, and moved about when required. The width of 
the border is marked on the floor, and wood screed rules 
laid level to the marks to form a fair joint line for the 
border, also as a screed when floating the centre part. 
The screed rules are generally fixed with a gauge plaster, 
which is quicker than fixing on gauged cement. After 
the centre is laid, the plaster should be carefully swept 
off, and the concrete well wetted before the border is laid. 
The marble and cement is gauged in the proportion of 2 
of marble to 1 of cement, and laid flush with screeds, 
laying and beating it in position with a long wood hand- 
float. The surface is ruled in from screed to screed with 
a straight-edge. The surface is then ironed with a lay¬ 
ing trowel until it is smooth and fair. If the marble 
does not show, or is not regular, or is insufficient, the 
bare parts are filled in with marble by hand. When 
marble is scarce, the % inch of the top surface is laid in 
two coats, the first being composed of cement and a 
cheaper aggregate, such as broken stone, tiles, &c., and 
gauged in the same proportion as the upper or marble 
coat. It is laid about % inch thick, and when it is firm, 
but not set, the marble coat is laid as before directed. 
The first coat saves the marble, and being firm, tends to 
keep the marble in the upper coat from sinking. The 
top coat is sometimes sprinkled over with fine marble 
chips by hand or through a fine sieve, then pressed into 
the surface and ironed with a laying trowel. Before 
ironing the surface, care should be taken that the chips 
are equally distributed, also that their flat surfaces are 
uppermost, and that the matrix and chips are perfectly 
solid and free from ridges and holes. After the centre 
is laid and the screeds removed, the border is laid in a 


336 


CEMENTS AND CONCRETES 


similar way. If there are two or more colors or forms in 
the border, the divisions are formed with narrow screed 
rules, and arranged so that as many as practicable can 
be laid at the same time. This allows the various parts 
to set at one time, and saves waiting for each separate 
part to set. The screed rules for circular work or angles 
are formed with strong gauged plaster and then oiled. 

The marble chips are either broken by hand or in a 
stone-breaking machine. The chips vary in size from 
1-10 to inch. The best colors for borders are a black 
matrix with white marble or spar chips, or a white 
matrix with black marble chips. The white matrix is 
obtained by mixing the marble dust (produced when 
breaking the marble into chips) with a light colored 
Portland cement. The centres can be made in various 
tints, but the most general is a warm red, which is ob¬ 
tained by mixing the cement with red oxide. Cement 
colored with red oxide should be laid first, as it is liable 
to stain other parts of a lighter color. When the centre 
and border are laid, the floor is left until the whole is 
perfectly set and hard, and it is then fit to polish. This 
is done by means of a stone polisher, water and marble 
dust, or fine slag powder. The stone polisher is a piece 
of hard stone from 8 to 12 inches square, and about 3 
inches thick, into which an iron ring is inserted and se¬ 
cured with lead. A wooden handle from 4 to 6 feet long, 
with an iron hook at one end, is inserted into the ring, 
so that the handle is firm on the stone, yet has sufficient 
play to be moved freely backwards and forwards. The 
polishing should not be attempted until the stuff is thor¬ 
oughly set, because the polishing will destroy the face 
of the cement, and cause a vast amount of extra labor in 
grinding the surface down until free from holes. Small 


HOW TO USE THEM 


337 


parts of the gauged stuff should be set aside as tests for 
determining when the stuff is set. Concrete mosaic, 
where economy is desirable, will make a strong, durable, 
and waterproof floor, and an excellent substitute for 
higher class mosaics. 

A Bulletin (No. 235), prepared by P. S. Wormley for 
the U. S. government on cement, mortar, and concrete, 
from which I quote at length, contains some excellent in¬ 
formation and instructions on the preparation and the 
use of the above materials. This bulletin is intended for 
free distribution and may be obtained by making appli¬ 
cation to the U. S. Department of Agriculture, Wash¬ 
ington, D. C. 

Storing Cement .—In storing cement care must be ex¬ 
ercised to insure its being kept dry. When no house or 
shed is available for the purpose, a rough platform may 
be erected clear of the ground, on which the cement may 
be placed and so covered as to exclude water. When 
properly protected, it often improves with age. Cement 
is shipped in barrels or bags, the size and weight of 
which usually are given. 

Cement Mortar .—Cement mortar is an intimate mix¬ 
ture of cement and sand mixed with sufficient water to 
produce a plastic mass. The amount of water will vary 
according to the proportion and condition of the sand, 
and had best be determined independently in each case. 
Sand is used both for the sake of economy and to avoid 
cracks due to shrinkage of cement in setting. Where 
great strength is required, there should be at least suffi¬ 
cient cement to fill the voids or air spaces in the sand, 
and a slight excess is preferable in order to compensate 
for any uneven distribution in mixing. Common propor¬ 
tions for Portland cement mortar are 3 parts sand to 1 


338 


CEMENTS AND CONCRETES 


of cement, and for natural cement mortar, 2 parts sand 
to 1 of cement. Unless otherwise stated, materials for 
mortar or concrete are considered to be proportioned by 
volume, the cement being slightly shaken in the measure 
used. 

A “lean” mortar is one having only a small propor¬ 
tion of cement, while a “rich” mixture is one with a 
large proportion of cement. “Neat” cement is pure 
cement, or that with no admixture of sand. The term 
11 aggregate 9 ’ is used to designate the coarse materials en¬ 
tering into concrete—usually gravel or crushed rock. 
The proportion in which the three elements enter into 
the mixture is usually expressed by three figures sepa¬ 
rated by dashes—as, for instance, 1-2-5, meaning 1 part 
cement, 2 parts sand, and 5 parts aggregate. In the 
great majority of cases cement mortar is subjected only 
to compression, and for this reason it would seem nat¬ 
ural that, in testing it, to determine its compressive 
strength. The tensile strength of cement mortar, how¬ 
ever, is usually determined, and from this its resistance 
to compression may be assumed to be from 8 to 12 times 
greater. A direct determination of the compressive 
strength is a less simple operation, for which reason the 
tensile test is in most cases accepted as indicating the 
strength of the cement. 

Mixing .—In mixing cement mortar it is best to use a 
platform of convenient size or a shallow box. First, de¬ 
posit the requisite amount of sand in a uniform layer, 
and on top of this spread the cement. These should be 
mixed dry with shovels or hoes, until the whole mass ex¬ 
hibits a uniform color. Next, form a crater of the dry 
mixture, and into this pour nearly the entire quantity of 
water required for the batch. Work the dry material 


HOW TO USE THEM 


339 


from the outside toward the centre, until all the water 
is taken up, then turn rapidly with shovels, adding water 
at the same time by sprinkling until the desired consist¬ 
ency is attained. It is frequently specified that the mor¬ 
tar shall be turned a certain number of times, but a bet¬ 
ter practice for securing a uniform mixture is to watch 
the operation and judge by the eye when the mixing has 
been carried far enough. In brick masonry the mis¬ 
take is frequently made of mixing the mortar very wet 
and relying upon the bricks to absorb the excess of 
water. It is better, however, to wet the brick thoroughly 
and use a stiff mortar. 

Grout .—The term ‘ ‘ grout ’ ’ is applied to mortar mixed 
with an excess of water, which gives about the consist¬ 
ency of cream. This material is often used to fill the 
voids in stone-masonry, and in brick work the inner por¬ 
tions of walls are frequently laid dry and grouted. The 
practice in either case is to be condemned, except where 
the conditions are unusual, as cement used in this way 
will never develop its full strength. 

Lime and Cement Mortar. —L. C. Sabin finds that in 
Portland cement mortar containing three parts sand to 
1 of cement, 10 per cent, of the cement may be replaced 
by lime in the form of paste without diminishing the 
strength of the mortar, and at the same time rendering it 
more plastic. In the case of natural cement mortar, lime 
may be added to the extent of 20 to 25 per cent, of the 
cement with good results. The increased plasticity due 
to the addition of lime much facilitates the operation of 
laying bricks, and has caused lime and cement mortar to 
be largely used. 

Cement Mortar for Plastering .—In plastering with 
cement, a few precautions must be observed to insure 


340 


CEMENTS AND CONCRETES 


good and permanent results. The surface to receive the 
plaster should be rough, perfectly clean, and well satu¬ 
rated with water. A mortar very rich in cement is 
rather a drawback than otherwise on account of shrink¬ 
age cracks, which frequently appear. The mortar, con¬ 
sisting of two or three parts sand to one of cement, 
should be mixed with as little water as possible and well 
worked to produce plasticity. It is essential that the 
plaster be kept moist until it has thoroughly hardened. 

Materials for Making Concrete Sand .—In securing 
sand for mixing mortar or concrete, if it is possible to 
select from several varieties, that sand should be chosen 
which is composed of sharp, angular grains, varying in 
size from coarse to fine. Such sand is, however, not 
always obtainable, nor is it essential for good work. Any 
coarse-grained sand which is fairly clean will answer 
the purpose. If gravel, sticks, or leaves be present they 
should be removed by screening. The voids in sand vary 
from 30 to 40 per cent., according to the variation in 
size of grains. A sand with different-sized grains is to 
be preferred, because less cement is required to fill the 
voids. By mixing coarse and fine sand it is possible to 
reduce the voids considerably. 

It is customary to use the terms “river sand,” “sea 
sand,” or “pit sand,” according to the source of the 
supply. River sand as a rule has rounded grains, but 
unless it contains an excess of clay or other impurities, it 
is suitable for general purposes. When river sand is of 
a light color and fine-grained it answers well for plaster¬ 
ing. 

Sea sand may contain the salts found in the ocean. 
The tendency of these salts to attract moisture makes it 


HOW TO USE THEM 


341 


advisable to wash sea sand before using it for plastering 
or other work which is to be kept perfectly dry. 

Pit sand for the most part will be found to have 
sharp, angular grains, which make it excellent for mor¬ 
tar or concrete work. Where clay appears in pockets it 
is necessary either to remove it, or else see that it is 
thoroughly mixed with the sand. The presence of clay in 
excess frequently makes it necessary to wash pit sand 
before it is suitable for use. 

The results of tests made in this laboratory would in¬ 
dicate that the presence of clay, even in considerable 
amounts, is a decided benefit to ‘ ‘ lean ’ ’ mortars, whereas 
it does not appreciably affect the strength of a rich 
mixture. 

Gravel .—It is important that gravel for use in con¬ 
crete should be clean, in order that the cement may prop¬ 
erly adhere to it, and form a strong and compact mass. 
As with sand, it is well to have the pieces vary in size, 
thereby reducing the voids to be filled with mortar. The 
voids in general range from 35 to 40 per cent. 

Crushed Stone .—The best stone for concrete work con¬ 
sists of angular pieces, varying in size and having a 
clean, rough surface. Some form of strong and durable 
rock is to be preferred, such as limestone, trap, or gran¬ 
ite. The total output of the crusher should be used be¬ 
low a maximum size, depending upon the nature of the 
work in hand. All material under % inch will act as so 
much sand and should be considered as such in propor¬ 
tioning the mixture. Precautions must be taken to in¬ 
sure a uniform distribution of the smaller pieces of stone, 
otherwise the concrete will have an excess of fine ma¬ 
terial in some parts and a deficiency in others. 


342 


CEMENTS AND CONCRETES 


Less than 8 per cent, of clay will probably not seri¬ 
ously impair the strength of the concrete, provided the 
stones are not coated with it, and may even prove a 
benefit in the case of lean mixtures. The voids in crushed 
stone depend upon the shape and variation in size of 
pieces, rarely falling below 40 per cent., unless much 
fine material is present, and in some cases reaching 50 
per cent. A mixture of stone and gravel in equal parts 
makes an excellent aggregate for concrete. 

S'tone Versus Gravel .—It would appear from tests that 
crushed stone makes a somewhat stronger concrete than 
gravel, but the latter is very extensively used with uni¬ 
formly good results. This superiority of stone over 
gravel for concrete work is attributed to the fact that the 
angular pieces of stone interlock more thoroughly than 
do the rounded pebbles, and offer a rougher surface to 
the cement. A point in favor of gravel concrete is that 
it requires less tamping to produce a compact mass than 
in the case of crushed stone. Then, too, the proportion 
of voids in stone being usually greater than in gravel, 
means a slight increase in the cost of concrete. 

Cinders .—Cinders concrete is frequently used in con¬ 
nection with expanded metal and other forms of rein¬ 
forcement for floor construction, and for this purpose it 
is well adapted on account of its light weight. Its poros¬ 
ity makes it a poor conductor of heat and permits the 
driving of nails. Only hard and thoroughly burned cin¬ 
ders should be used, and the concrete must be mixed 
quite soft so as to require but little tamping and to avoid 
crushing the cinders. Cinder concrete is much weaker, 
both in tension and compression, than stone or gravel 
concrete, and for this reason admits only of light rein¬ 
forcement. 


HOW TO USE THEM 


343 


Concrete .—General Discussion: Cement concrete is 
the product resulting from an intimate mixture of 
cement mortar with an aggregate of crushed stone, 
gravel, or similar material. The aggregate is crushed or 
screened to the proper size as determined from the char¬ 
acter of the work. In foundation work, stone or gravel 
3 inches in size may be used to advantage, whereas in the 
case of moulded articles of small sectional area, such as 
fence posts, hollow building blocks, &c., it is best to use 
only such material as will pass a y 2 inch screen. An 
ideal concrete, from the standpoint of economy, would 
be that in which all voids in the aggregate were com¬ 
pletely filled with sand, and all the voids in the sand 
completely filled with cement, without any excess. Un¬ 
der these conditions there would be a thoroughly com¬ 
pact mass and no waste of materials. 

It is a simple matter to determine the voids in sand 
and also in the aggregate, but in mixing concrete the 
proportions vary a great deal, depending in each case 
upon the nature of the work and the strength desired. 
For example, in the construction of beams and floor pan¬ 
els, where maximum strength with minimum weight is 
desired, a rich concrete should be used, whereas in mas¬ 
sive foundation work, in which bulk or weight is the 
controlling factor, economy would point to a lean mix¬ 
ture. When good stone or gravel is used, the strength of 
the concrete depends upon the strength of the mortar em¬ 
ployed in the mixing and the proportion of mortar to 
aggregate. For a given mortar the concrete will be 
strongest when only enough mortar is used to fill the 
voids in the aggregate, less strength being obtained by 
using either greater or less proportion. In practice it is 


344 


CEMENTS AND CONCRETES 


usual to add a slight excess of mortar over that required 
to fill the voids in the aggregate. 

It is more accurate to measure cement by weight un¬ 
less the unit employed be the barrel or sack, because 
when taken from the original package and measured in 
bulk there is a chance of error due to the amount of 
shaking the cement receives. As it is less convenient, 
however, to weigh the cement, it is more usual to 
measure it by volume, but for the reasons stated this 
should be done with care. 

Proportioning Materials .—For an accurate determina¬ 
tion of the best and most economical proportions where 
maximum strength is required, it is well to proceed in 
the following way: First, proportion the cement and 
sand so that the cement paste will be 100 per cent, in ex¬ 
cess of the voids in sand; next, determine the voids in 
the aggregate and allow sufficient mortar to fill all voids, 
with an excess of 10 per cent. 

To determine roughly the voids in gravel or crushed 
stone prepare a water-tight box of convenient size and 
fill with the material to be tested, shake well and smooth 
off even with the top. Into this pour water until it rises 
flush with the surface. The volume of water added, 
divided by the volume of the box, measured in the same 
units, represents the proportion of voids. The propor¬ 
tion of voids in sand may be more accurately determined 
by subtracting the weight of a cubic foot of packed sand 
from 165, the weight of a cubic foot of quartz, and divid¬ 
ing the difference by 165 degrees. 

The following will serve as an example of proportion¬ 
ing materials: Assume voids in packed sand to measure 
38 per cent., and voids in packed stone to measure 48 
per cent. Cement paste required per cubic foot of sand, 


HOW TO USE THEM 


345 


0.38 and 1-10 equals 0.42 cubic foot, approximately. By 
trial, 1 cubic foot of loose cement, lightly shaken, makes 
0.85 cubic foot of cement paste, and requires yff- or 
2 cubic feet of sand, approximately, producing an 
amount of mortar equal to 0.85 and 2 (1-0.38) equals 
2.09 cubic feet. Mortar required per cubic foot of stone 
equals 0.48, and 1-10x0.48 equals 0.528 cubic foot. There¬ 
fore 2.09 cubic feet mortar will require |^| equals 
4 cubic feet of stone, approximately. The proportions 
are therefore 1 part cement, 2 parts sand, 4 parts stone. 
Although such a determination is usually considered un¬ 
necessary in practical work, it may be of sufficient inter¬ 
est to justify giving it. 

For general use the following mixtures are recom¬ 
mended : 1 cement, 2 sand, 4 aggregate, for very strong 
and impervious; 1 cement, 2 y 2 sand, 5 aggregate, for 
ordinary work requiring moderate strength; 1 cement, 3 
sand, 6 aggregate, for work where strength is of minor 
importance. 

Aggregate Containing Fine Material .—In the case of 
gravel containing sand, or crushed stone from which the 
small articles have not been removed by screening, the 
amount of such fine sand or fine stone should be deter¬ 
mined and due allowance made for it in proportioning 
the mortar. 

When mixing an aggregate containing small particles 
with mortar, and in reality we have a mortar containing 
a larger proportion of sand than was present before the 
aggregate was incorporated. It is evident, then, that in 
such cases the quality of richness of the mortar should 
depend upon the proportion of fine material in the ag¬ 
gregate. 


346 


CEMENTS AND CONCRETES 


For example, suppose that 1 cubic foot of gravel con¬ 
tains 0.1 cubic foot of sand, and that the voids in gravel 
with sand screened out measure 40 per cent. For gen¬ 
eral purposes this would suggest a 1-2-5 mixture, but 
since each cubic foot contains 0.1 cubic foot sand, 5 
cubic feet gravel will contain 0.5 cubic foot sand, and 
the proportions should be changed to 1 part cement, 1% 
parts sand, 5 parts gravel. 

Mechanical Mixers .—It has been demonstrated that 
concrete can be mixed by machinery as well, if not bet¬ 
ter, than by hand. Moreover, if large quantities of con¬ 
crete are required, a mechanical mixer introduces marked 
economy in the cost of construction. None of the various 
forms of mechanical mixers will be described here, since 
concrete in small quantities, as would be used on the 
farm, is more economically mixed by hand. 

Mixing by Hand .—In mixing by hand a platform is 
constructed as near the work as is practicable, the sand 
and aggregate being dumped in piles at the side. If the 
work is to be continuous, this platform should be of suf¬ 
ficient size to accommodate two batches, so that one batch 
can be mixed as the other is being deposited. The ce¬ 
ment must be kept under cover and well protected from 
moisture. A convenient way of measuring the materials 
Is by means of a bottomless box or frame made to hold 
the exact quantities needed for a batch. 

A very common and satisfactory method of mixing 
concrete is as follows: First measure the sand and ce¬ 
ment required for a batch and mix these into mortar as 
described on page 5. Spread out this mortar in a thin 
layer and on top of it spread the aggregate, which has 
been previously measured and well wetted. The mixing 
is done by turning with shovels three or more times, as 


HOW TO USE THEM 


347 


may be found necessary to produce a thoroughly uni¬ 
form mixture, water being added if necessary to give 
the proper consistency. The mixers, two or four in num¬ 
ber, according to the size of the batch, face each other 
and shovel to right and left, forming two piles, after 
which the material is turned back into a pile at the cen¬ 
tre. By giving the shovel a slight twist, the material is 
scattered in leaving it and the efficiency of the mixing 
is much increased. 

Consistency of Concrete .—A dry mixture, from which 
water can be brought to the surface only by vigorous 
tamping, is probably the strongest, but for the sake of 
economy, and to insure a dense concrete well filling the 
moulds a moderately soft mixture is recommended for 
ordinary purposes. Where the pieces to be moulded are 
thin, and where small reinforcing metal rods are placed 
close together or near the surface, a rather wet mixture 
may be necessary to insure the moulds being well filled. 

TJse of Quick-Setting Cement .—In the manufacture 
of such articles as pipe, fence posts, and hollow blocks, 
a rather large proportion of quick-setting cement is 
sometimes used, the object being to reduce the weight 
and consequent freight charges by means of a strong 
mixture, as well as to make the concrete impervious to 
water. The use of a quick-setting cement permits the 
moulds to be removed sooner than would be possible with 
a slow-setting cement, thus reducing the number of 
moulds necessary for a given output. Quick-setting ce¬ 
ments are not recommended for sucli purposes, however, 
as they are usually inferior to those which set slowly. 

Coloring Cement Work .—In coloring cement work the 
best results are obtained by the use of mineral pig¬ 
ment. The coloring matter, in proportions depending 


348 


CEMENTS AND CONCRETES 


upon the desired shade, should be thoroughly mixed with 
the dry cement before making the mortar. By prepar¬ 
ing small specimens of the mortar and noting the color 
after drying, the proper proportions may be determined. 

For gray or black, use lampblack. 

For yellow or buff, use yellow ochre. 

For brown, use umber. 

For red, use Venetian red. 

For blue, use ultramarine. 

Depositing Concrete .—Concrete should be deposited 
in layers of from 4 to 8 inches and thoroughly tamped 
before it begins to harden. The tamping required will 
depend upon the consistency of the mixture. If mixed 
very dry it must be vigorously rammed to produce a 
dense mass, but as the proportion of water increases less 
‘tamping will be found necessary. Concrete should not 
be dumped in place from a height of more than 4 feet, 
unless it is again mixed at the bottom. A wooden in¬ 
cline may be used for greater heights. Rammers for 
ordinary concrete work should weigh from 20 to 30 
pounds and have a fade not exceeding 6 inches square. 
A smaller face than this is often desirable, but a larger 
one will be less effective in consolidating the mass. In 
cramped situations special forms must be employed to 
suit the particular conditions. When a thickness of 
more than one layer is required, as in foundation work, 
two or more layers may be worked at the same time, each 
layer slightly in advance of the one next above it and 
ail being allowed to set together. At the end of a day 
there is usually left a layer partially completed which 
must be finished the next day. This layer should not be 
beveled off, but the last batch of concrete should be 
tamped behind a vertical board forming a step. 


HOW TO USE THEM 


349 


To avoid introducing a plane of weakness where fresli 
concrete is deposited upon that which has already set, 
certain precautions have to be observed. The surface of 
the old work should be clean and wet before fresh ma¬ 
terial is put on, a thin coat of neat cement grout being 
sometimes employed to insure a good bond. The sur¬ 
face of the concrete to receive an additional layer must 
not be finished off smoothly, but should offer a rough 
surface to bond with the next layer. This may be done 
by roughing the surface while soft with pick and shovel, 
or the concrete may be so rammed as to present a rough 
and uneven surface. Wooden blocks or scantling are 
sometimes embedded several inches in the work and re¬ 
moved before the concrete hardens, thus forming holes 
or grooves to be filled by the next layer. 

Retempering .—As stated before, it is important that 
concrete be tamped in place before it begins to harden, 
and for this reason it is proper to mix only so much at a 
time as is required for immediate use. The retempering 
of concrete which has begun to set is a point over which 
there is much controversy. From tests made in this 
laboratory it would appear that such concrete suffers but 
little loss of strength if thoroughly mixed with sufficient 
water to restore normal consistence. 

The time required for concrete to set depends upon 
the character of the cement, upon the amount and tem¬ 
perature of the water used in mixing, and upon the 
temperature of the air. Concrete mixed dry sets more 
quickly than if mixed wet, and the time required for 
setting decreases as the temperature of the water rises. 
Warm air also hastens the setting. 

Concrete Exposed to Sea-Water .—Portland cement 
concrete is well adapted for work exposed to sea-water, 


350 


CEMENTS AND CONCRETES 


but when used for this purpose it should be mixed with 
fresh water. The concrete must be practically imper¬ 
vious, at least on the surfaces, and to accomplish this 
purpose the materials should be carefully proportioned 
and thoroughly mixed. It is also of great importance 
that the concrete be well compacted by tamping, par¬ 
ticularly on exposed surfaces. 

Concrete Work in Freezing Weather .—Although it is 
advisable under ordinary conditions to discontinue ce¬ 
ment work in freezing weather, Portland cement may be 
used without serious difficulty by taking a few simple 
precautions. As little water as possible should be used 
in mixing, to hasten the setting of the concrete. To 
prevent freezing, hot water is frequently used in mixing 
mortar or concrete, and with the same object in view salt 
is added in amounts depending upon the degree of cold. 
A common practice is to add 1 pound of salt to 18 gal¬ 
lons of water, with the addition of 1 oz. of salt for each 
degree below 32° F. Either of the above methods will 
give good results, but it should be remembered that the 
addition of salt often produces efflorescence. It seems 
to be a fairly well-established fact that concrete de¬ 
posited in freezing weather will ultimately develop full 
strength, showing no injury due to the low temperature. 

Bubble Concrete .—In massive concrete work consider¬ 
able economy may often be introduced by the use of 
large stones in the body of the work, but only in heavy 
foundations, retaining walls, and similar structures 
should this form of construction be permitted. In plac¬ 
ing these large stones in the work the greatest care must 
be exercised to insure each being well bedded, and the 
concrete must be thoroughly tamped around them. Each 


HOW TO USE THEM 


351 


stone should be at least 4 inches from its neighbor and 
an equal distance from the face of the work. 

To Face Concrete. —A coating of mortar one-half 
inch in thickness is frequently placed next the form to 
prevent the stone or gravel from showing and to give 
a smooth and impervious surface. If in preparing this 
mortar finely crushed stone is used instead of sand, th* 



NO, 6. 

work will more nearly resemble natural stone. A 
common method employed in facing concrete is to pro¬ 
vide a piece of thin sheet metal of convenient length 
and about 8 to 10 inches wide. To this pieces of angle 
iron are riveted, so that when placed next to the mould 
a narrow space is formed in which the cement mortar is 
placed after the concrete has been deposited behind it. 
(No. 6.) The metal plate is then withdrawn and the 





















































































352 


CEMENTS AND CONCRETES 


concrete well tamped. The concrete and facing mor¬ 
tar must be put in at the same time so that they will 
set together. If the concrete is fairly rich, a smooth 
surface can usually be produced without a facing of 
mortar by working a spade up and down between the 
concrete and inner face of the mould, thus forcing the 
larger pieces of the aggregate back from the surface. 

Wood for Forms .—Lumber used in making forms for 
concrete should be dressed on one side and both edges. 
The expansion and distortion of the wood due to the 
absorption of water from the concrete frequently make 
it difficult to produce an even surface on the work, and 
unless the forms are accurately fitted together more or 
less water will find its way out through the cracks, 
carrying some of the cement with it. A method some¬ 
times adopted to minimize the effect of expansion is to 
bevel one edge of each board, allowing this edge to 
crush against the square edge of the adjacent board 
when expansion takes place. In the case of a wooden 
core or inside mold, expansion must always be taken into 
consideration, for if neglected it may cause cracks or 
complete rupture of the concrete. Sharp edges in con¬ 
crete are easily chipped and should be avoided by plao 
ing triangular strips to the corners of moulds. To pre¬ 
vent cement from sticking to the forms they may be 
given a coating of soft soap or be lined with paper. 
This greatly facilitates their removal and enables them 
to be used again with but little scraping. A wire brush 
answers best for cleaning the forms. 

Concrete Sidewalks .—A useful and comparatively 
simple application of concrete is in the construction of 
sidewalks, for which purpose it has been used with 
marked success for a number of years. 


HOW TO USE THEM 


353 


Excavation and Preparation of Subgrade .—The 
ground is excavated to subgrade and well consolidated 
by ramming to prepare it for the subfoundation of 
stone, gravel or cinders. The depth of excavation will 
depend upon the climate and nature of the ground, 
being deeper in localities where heavy frosts occur or 
where the ground is soft than in climates where there 
are no frosts. In the former case the excavation should 
be carried to a depth of 12 inches, whereas in the latter 
from 4 to 6 inches will be sufficient. No roots of trees 
should be left above the sub grade. 

The Subfoundation .—The foundation consists of a 
layer of loose material, such as broken stone, gravel, 
or cinders, spread over the subgrade and well tamped to 
secure a firm base for the main foundation of concrete 
which is placed on top. It is most important that the 
subfoundation be well drained to prevent the accumula¬ 
tion of water, which, upon freezing, would lift and crack 
the walk. For this purpose it is well to provide drain 
tile at suitable points to carry off any water which may 
collect under the concrete. An average thickness for 
subfoundation is 4 to 6 inches, although in warm cli¬ 
mates, if the ground is firm and well drained, the sub¬ 
foundation may only be 2 to 3 inches thick or omitted 
altogether. 

The Foundation .—The foundation consists of a layer 
of concrete deposited on the subfoundation and carry¬ 
ing a surface layer or wearing coat of cement mortar. If 
the ground is firm and the subfoundation well rammed 
in place and properly drained, great strength will not be 
required of the concrete, which may, in such cases, be 
mixed in about the proportions 1-3-6, and a depth of only 
3 to 4 inches will be required. Portland cement should 


354 


CEMENTS AND CONCRETES 


be used and stone or gravel under 1 inch in size, the con¬ 
crete being mixed of medium consistency, so that 
moisture will show on the surface without excessive 
tamping. 

The Top Dressing or Wearing Surface .—To give a 
neat appearance to the finished walk, a top dressing, of 
cement mortar is spread over the concrete, well worked 
in, and brought to a perfectly smooth surface with 
straightedge and float. This mortar should be mixed 
in the proportion 1 part cement to 2 parts sand, sharp 
coarse sand or screenings below one-fourth inch of some 
hard, tough rock being used. The practice of making 
the concrete of natural cement and the wearing surface 
of Portland is not to be commended, owing to a tendency 
for the two to separate. 

Details of Construction .—A cord stretched between 
stakes will serve as a guide in excavating, after which 
the bottom of the trench is well consolidated by ram¬ 
ming; any loose material below subgrade is then spread 
over the bottom of the trench to the desired thickness 
and thoroughly compacted. Next, stakes are driven 
along the sides of the walk; spaced 4 to 6 feet apart, 
and their tops made even with the finished surface of 
the walk, which should have a transverse slope 
of one-fourth inch to the foot for drainage. Wooden 
strips at least iy 2 inches thick and of a suitable depth 
are nailed to these stakes to serve as a mould to concrete. 
By carefully adjusting these strips to the exact height of 
the stakes they friay be used as guides for the straight¬ 
edge in levelling off the concrete and wearing surface. 
The subfoundation is well sprinkled to receive the con¬ 
crete, which is deposited in the usual manner, well 
tamped behind a board set vertically across the trench, 


HOW TO USE THEM 


355 


and levelled off with a straightedge as shown in Fig. 7, 
leaving one-half to 1 inch for the wearing surface. 
Three-eighths inch sand joints are provided at intervals 
of 6 to 8 feet to prevent expansion cracks, or, in case of 
settlement, to confine the cracks to these joints. This is 
done either by depositing the concrete in sections, or by 
dividing it into such sections with a spade when soft and 
filling the joints with sand. The location of each joint 
is marked on a wooden frame for future reference. 



NO. 7. 

Care must be exercised to prevent sand or any other 
material from being dropped on the concrete, and thus 
preventing a proper union with the wearing surface. No 
section should be left partially completed to be finished 
with the next batch or left until the next day. Any con¬ 
crete left after the completion of a section should be 
mixed with the next batch. 

It is of the utmost importance to follow up closely the 
concrete work with the top dressing in order that the 







356 


CEMENTS AND CONCRETES 


two may set together. This top dressing should be 
worked well over the concrete with a trowel, and levelled 
with a straightedge (No. 7) to secure an even surface. 
Upon the thoroughness of this operation often depends 
the success or failure of the walk, since a good bond be¬ 
tween the wearing surface and concrete base is absolute¬ 
ly essential. The mortar should be mixed rather stiff. 
As soon as the film of water begins to leave the surface, 
a wooden float is used, followed up by a plasterer’s 
trowel, the operation being similar to that of plastering 
a wall. The floating, though necessary to give a smooth 
surface, will, if continued too long, bring a thin layer of 
neat cement to the surface and probably cause the walk 
to crack. 



Jointer used in dividing walk 
into sections. 


NO. 8. 

The surface is now divided into sections by cutting en¬ 
tirely through, exactly over the joints in the concrete. 
This is done with a trowel guided by a straightedge, 
after which the edges are rounded off with a special tool 
called a jointer, having a thin shallow tongue (No. 8). 
These sections may be subdivided in any manner desired 
for the sake of appearance. 

A special tool called an edger (No. 9) is run round the 
outside of the walk next to the mould, giving it a neat 
rounded edge. A toothed roller (No. 10) having small 


HOW TO USE THEM 


357 


projections on its face is frequently used to produce 
slight indentations on the surface, adding somewhat to 



Tool used in rounding edges. 

NO. 9. 

the appearance of the walk. The completed work must 
be protected from the sun and kept moist by sprinkling 



•Roller used in finishing surface 
NO. 10. 


for several days. In freezing weather the same precau¬ 
tions should be taken as in other classes of concrete 
work. 








358 


CEMENTS AND CONCRETES 


Concrete Basement Floors .—Basement floors in dwell¬ 
ing houses as a rule require only a moderate degree of 
strength, although in cases of very wet basements, where 
water pressure from beneath has to be resisted, greater 
strength is required than would otherwise be necessary. 
The subfoundation should be well drained, sometimes re¬ 
quiring the use of tile for carrying off the water. The 
rules given for constructing concrete sidewalks apply 
equally well to basement floors. The thickness of the 
concrete foundation is usually from 3 to 5 inches, ac¬ 
cording to the strength desired, and for average work a 
1-3-6 mixture is sufficiently rich. Expansion joints are 
frequently omitted, since the temperature variation is 
less than in outside work, but since this omission fre¬ 
quently gives rise to unsightly cracks, their use is recom¬ 
mended in all cases. It will usually be sufficient to 
divide a room of moderate size into four equal sections, 
separated by % inch sand joints. The floor should be 
given a slight slope toward the center or one corner, with 
provision at the lowest point for carrying off any water 
that may accumulate. 

Concrete Stable Floors and Driveways .—Concrete 
stable floors and driveways are constructed in the same 
general way as basement floors and sidewalks, but with 
a thicker foundation, on account of the greater strength 
required. The foundation’ may well be 6 inches thick, 
with a 10 inch wearing surface. An objection often 
sometimes raised against concrete driveways is that they 
become slippery when wet; but this fault is in a great 
measure overcome by dividing the wearing surface into 
Small squares about 4 inches on the side, by means of tri¬ 
angular grooves % of an inch deep. This gives a very 


HOW TO USE THEM 


359 


neat appearance and furnishes a good foothold for 
horses. 

Concrete Steps .—Concrete may be advantageously 
used in the construction of steps, particularly in damp 
places, such as areaways and cellars of houses, and in 
the open, where the ground is terraced, concrete steps 
and walks can be made exceedingly attractive. Where 
the ground is firm it may be cut away as nearly as pos¬ 
sible in the form of steps, with each step left two or 
three inches below its finished level. The steps are 
formed, beginning at the top, by depositing the con- 



NO. 11. 

Crete behind vertical boards so placed as to give the nec¬ 
essary thickness to the risers and projecting high enough 
to serve as a guide in leveling off the tread. Such steps 
may be reinforced where greater strength is desired or 
where there is danger of cracking, due to the settlement 
of the ground. 

Where the nature of the ground will not admit of its 
being cut away in the form of steps, the risers are 






360 


CEMENTS AND CONCRETES 


molded between two vertical forms. The front one may 
be a smooth board, but the other should be a piece of 
thin sheet metal, which is more easily removed after the 
earth has been tamped in behind if. A simple method 
of reinforcing steps is to place a y 2 inch steel rod in each 
corner, and thread these with % inch rods bent to the 
shape of the steps, as shown in No. 11 , the latter being 
placed about 2 feet apart. For this class of work a rich 
Portland cement concrete is recommended, with the use 
of stone or gravel under y 2 inch in size. Steps may be 
given a % inch wearing surface of cement mortar mixed 
in the proportion of 1 part cement to 2 parts sand. This 
system, as well as many others, is well adapted for stair¬ 
ways in houses. 

Reinforced Concrete Fence Posts .—Comparison of dif¬ 
ferent Post Materials: There is a constantly increasing 
demand for some form of fence posts which is not sub¬ 
ject to decay. The life of wooden posts is very limited, 
and the scarcity of suitable timber in many localities 
has made it imperative to find a substitute. A fence 
post, to prove thoroughly satisfactory, must fulfil three 
conditions: (1) It must be obtainable cost; (2) it must 
possess sufficient strength to meet the demands cf gen¬ 
eral farm use; (3) it must not be subject to decay, and 
must be able to withstand successfully the effects of 
water, frost and fire. Although iron posts of various 
designs are frequently used for ornamental purposes, 
their adoption for general farm use is prohibited by their 
excessive cost. Then, too, iron posts exposed to the 
weather are subject to corrosion, to prevent which neces¬ 
sitates repainting from time to time, and this item will 
entail considerable expense in cases where a large num¬ 
ber of posts are to be used. 


HOW TO USE THEM 


361 


At the present time the material which seems most 
nearly to meet these requirements is reinforced con¬ 
crete. The idea of constructing fence posts of concrete 
reinforced with iron or steel is by no means a new one., 
but, on the contrary, such posts have been experimented 
with for years, and a great number of patents have been 
issued covering many of the possible forms of reinforce¬ 
ment. It is frequently stated that a reinforced con¬ 
crete post can be made and put in the ground for the 
same price as a wooden post. Of course this will de¬ 
pend in any locality upon the relative value of wood and 
the various materials which go to make up the concrete 
post, but in the great majority of cases wood will prove 
the cheaper material in regard to first cost. On the 
other hand, a concrete post will last indefinitely, its 
strength increasing with age, whereas the wooden post 
must be replaced at short intervals, probably making it 
more expensive in the long run. 

In regard to strength, it must be borne in mind that 
it is not practicable to make concrete fence posts as 
strong as wooden posts of the same size; but since wooden 
posts, as a rule, are many times stronger than is neces¬ 
sary, this difference in strength should not condemn the 
use of reinforced concrete for this purpose. Moreover, 
strength in many cases is of little importance, the fence 
being used only as a dividing line, and in such cases 
small concrete posts provide ample strength and present 
a very uniform and neat appearance. In any case, to 
enable concrete posts to withstand the loads they are 
called upon to carry, sufficient strength may be secured 
by means of reinforcement, and where great strength is 
required this may be obtained by using a larger post 
with a greater proportion of metal and well braced, as 


362 


CEMENTS AND CONCRETES 


is usual in such cases. In point of durability, concrete 
is unsurpassed by any material of construction. It offers 
a perfect protection to the metal reinforcement and is 
not itself affected by exposure, so that a post constructed 
of concrete reinforced with steel will last indefinitely and 
require no attention in the way of repairs. 

Reinforcement .—No form of wooden reinforcement, 
either on the surface or within the post, can be recom¬ 
mended. If on the surface, the wood will soon decay, 
and if a wooden core is used it will, in all probability, 
swell by the absorption of moisture and crack the post. 
The use of galvanized wire is sometimes advocated, but 
if the post is properly constructed and a good concrete 
used, this precaution against rust will be unnecessary, 
since it has been fully demonstrated by repeated tests 
that concrete protects steel perfectly from rust. If 
plain, smooth wire or rods are used for reinforcement 
they should be bent over at the ends or looped to pre¬ 
vent slipping in the concrete. Twisted fence wire may 
usually be obtained at a reasonable cost and is very well 
suited for this purpose. Barbed wire has been proposed 
and is sometimes used, although the barbs make it ex¬ 
tremely difficult to handle. For the sake of economy the 
smallest amount of metal consistent with the desired 
strength must be used, and this requirement makes it 
necessary to place the reinforcement near the surface, 
where its strength is utilized to greatest advantage, with 
only enough concrete on the outside to form a protective 
covering. A reinforcing member in each corner of the 
post is probably the most efficient arrangement. 

Concrete for Fence Posts .—The concrete should be 
mixed with Portland cement in about the proportions 
1 -2y 2 -5, broken stone or gravel under y 2 inch being used. 


HOW TO USE THEM 


363 


In cases where the aggregate contains pieces smaller 
than 1/4 inch, less sand may be used, and in some cases 
it may be omitted altogether. A mixture of medium con¬ 
sistency is recommended on the ground that it fills the 
molds better and with less tamping than if mixed quite 
dry. 

Molds for Fence Posts .—Economy points to the use 
of a tapering post, which, fortunately, offers no diffi¬ 
culties in the way of molding. All things considered, 



Wooden gold for making fence posts with four tapering sides. 
NO. 12. 


wooden molds will be found most suitable. They can 
easily and quickly be made in any desired form and size. 
Posts may be molded either in a vertical or horizontal 
position, the latter being the simpler and better method. 
If molded vertically a wet mixture is necessary, requir¬ 
ing a longer time to set, with the consequent delay in 
removing the molds. No. 12 shows a simple mold, which 
has been used with satisfactory results in this laboratory. 








364 


CEMENTS AND CONCRETES 


This mold has a capacity of four pests, but larger molds 
could easily be made on the same principle. It consists 
of two end pieces, (a) carrying lugs, (b) between which 
are inserted strips (c). The several parts are held to¬ 
gether with hooks and eyes, as shown in No. 12. To pre¬ 
vent any bulging of the side strips they are braced, as 
illustrated. Dressed lumber at least 1 inch thick, and 
preferably 1 y 2 inches, should be used. In No. 12 the 



NO. 13. 


post measures 6 by 6 inches at the bottom, 6 by 3 at the 
top, and 7 feet in length, having two parallel sides. If 
it is desired to have the posts square at both ends the 
mold must be arranged as in No. 13. This latter form 
of post is not as strong as the former, but requires less 
concrete in its construction. Great care in tamping is 
necessary to insure the corners of the mold being well 








HOW TO USE THEM 


365 


filled, and if this detail is not carefully watched, the 
metal, being exposed in places, will be subject to rust. 

Attaching Fence Wires to Posts .—Various devices have 
been suggested for attaching fence wires to the posts, the 
object of each being to secure a simple and permanent 
fastener or one admitting of easy renewal at any time. 
Probably nothing will answer the purpose better than a 
long staple or bent wire well embedded in the concrete, 
being twisted or bent at the end to prevent extraction. 
Galvanized metal must be used for fasteners, since they 



•Detail showing method of at* 
taching wire to post. 


NO. 14. 

are not protected by the concrete. A piece of small flex¬ 
ible wire, about two inches in length, threading the staplf 
and twisted several times with a pair of pliers, holds the 
line wire in position. (No. 14.) 

Molding and Curing Posts .—For the proper method of 
mixing concrete see previous pages. It is recommended 
that only so much concrete be mixed at one time as can 
be used before it begins to harden; but if an unavoidable 
delay prevents the posts being molded until after the 









366 


CEMENTS AND CONCRETES 


concrete has begun to set, it is thought that a thorough, 
regauging with sufficient water to restore normal con¬ 
sistency will prevent any appreciable loss of strength, 
though the concrete may have been standing one or two 
hours. In using a mold similar to those illustrated in 
Nos. 12 and 13 it is necessary to provide a perfectly 
smooth and even platform of a size depending upon the 
number of posts to be molded. A cement floor if accessi¬ 
ble may be used to advantage. The moldis when in place 
are given a thin coating of soft soap, the platform or 
cement floor, serving as bottom of mold, being treated in 
the same way. About 1% inches is spread evenly over 
the bottom and carefully tamped, so as to reduce it to a 
thickness of about 1 inch. A piece of board cut as in 
No. 12 will be found useful in leveling off the concrete to 
the desired thickness before tamping. On top of this 
layer two reinforcing members are placed about 1 inch 
from the sides of the mold. The molds are then filled 
and tamped in thin layers to the level of the other two 
reinforcing members, the fasteners for fence wires being 
inserted during the operation. These reinforcing mem¬ 
bers are adjusted as were the first two, and the remain¬ 
ing 1 inch of concrete tamped and leveled off, thus com¬ 
pleting the post so far as molding is concerned. To avoid 
sharp edges, which are easily chipped, triangular strips 
may be placed in the bottom of mold along the sides, and 
when the molds have been filled and tamped, similar 
strips may be inserted on top. The top edges may be 
beveled with a trowel or by running an edging tool hav¬ 
ing a triangular projection on its bottom along the edges. 
Such a tool is shown in No. 15, and can easily be made 
of wood or metal. It is not necessary to carry the bevel 
below the ground line. 


HOW TO USE THEM 


367 


The ends and sides of the mold may be removed after 
twenty-four hours, but the posts should not be handled 
for at least one week, during which time they must be 
well sprinkled several times daily and protected from sun 
and wind. The intermediate strips may be carefully 
withdrawn at the end of two or three days, but it is bet¬ 
ter to leave them in place until the posts are removed. 
Although a post may be hard and apparently strong 
when one week old 2 it will not attain its full strength in 
that length of time, and must be handled with the utmost 
care to prevent injury. Carelessness in handling green 
posts frequently results in the formation of fine cracks, 
which though unnoticed at the time, give evidence of 
their presence later in the failure of the posts. 



posts. 
NO. 15. 


Posts should be allowed to cure for at least sixty days 
before being placed in the ground, and for this purpose 
it is recommended that when moved from the molding 
platform they be placed upon a smooth bed of moist sand 
and protected from the sun until thoroughly cured. Dur¬ 
ing this period they should receive a thorough drench¬ 
ing at least once a day. 



368 


CEMENTS AND CONCBETES 


The life of the molds will depend upon the care with 
which they are handled. A coating of mineral oil or 
shellac may be used instead of soap to prevent the cement 
from sticking to the forms. As soon as the molds are 
removed they should be cleaned with a wire brush before 
being used again. 

The cost of reinforced concrete fence posts depends 
in each case upon the ccst of labor and materials, and 
must necessarily vary in different localities. An esti¬ 
mate in any particular case can be made as follows: One 
cubic yard of concrete will make twenty posts measuring 
6 inches by 6 inches at the bottom, 6 inches by 3 inches 
at the top, and 7 feet long, and if mixed in the propor¬ 


tions 1 -2y 2 -5, requires approximately: 

1.16 barrels of cement, at $2. $2.32 

0.44 cubic yard of sand, at 75 cts.33 

0.88 cubic yard of gravel, at 75 cts.66 


Materials for 1 cubic yard cement.$3.21 

Concrete for one post. 17 

28 feet of 0.16 inch steel wire, at 3 cts a pound.06 


Total cost of concrete and metal for 1 post.23 


To this must be added the cost of mixing concrete, 
molding and handling posts, and the costs of molds, an 
addition which should not in any case exceed 7 cents, 
making a total of 30 cents per post. 

Concrete Building Blocks— Concrete building blocks, 
or cement blocks, as they are frequently called, are more 
extensively used now than ever before. These blocks 
are molded hollow primarily to reduce their cost, but 
this hollow construction serves other useful purposes at 
the same time. The fundamental principles governing 










HOW TO USE THEM 


369 


ordinary concrete work, so far as proportioning and 
mixing materials is concerned, apply equally well to the 
manufacture of building blocks, and it should be borne 
in mind that strength and durability can not be obtained 
by the use of any machine unless the cement, sand, and 
aggregate are of good quality, properly proportioned 
and well mixed. The aggregate for blocks of ordinary 
size should be crushed stone or gravel not larger than 
y 2 inch. One of the chief causes of complaint against 
the concrete building block is its porosity, but this defect 
is in a great measure due to the fact that in an endeavor 
to economize too little cement is frequently used. It is 
not unusual to give the blocks a facing of cement mor¬ 
tar consisting of about 2 parts sand to 1 of cement, while 
the body of the block is composed of a concrete of suffi¬ 
cient strength, though not impervious. This outside 
layer of mortar adds practically nothing to the strength 
of the block, and is used simply to give a uniform sur¬ 
face and to render the face of the wall more clearly im¬ 
pervious to water. 

It would not be practicable as a rule to attempt the 
manufacture of concrete blocks without one of the many 
forms of molding machines designed for the purpose, noi 
would it be economical to purchase such a machine un¬ 
less a sufficient number of blocks were required to justify 
such an outlay. Blocks in almost any desired shape and 
size, with either plain or ornamental faces, may be ob¬ 
tained on the market, and in the great majority of cases 
it is best to buy them from some reliable firm. Among 
the advantages claimed for hollow concrete block con¬ 
struction may be mentioned the following: 

(1) Hollow block construction introduces a saving of 
material over brick or stone masonry. 


370 


CEMENTS AND CONCRETES 


(2) The cost of laying concrete blocks is less than for 
brick work. This is due to the fact that the blocks, being 
larger, require a much smaller number of joints and 
less mortar, and, being hollow, are of less weight than 
solid brick work. 

(3) A wall constructed of good concrete blocks is as 
strong or stronger than a brick wall of equal thickness. 

(4) Concrete blocks, being easily molded to any de¬ 
sired form, will prove to be a far more economical build¬ 
ing material than stone, which has to be dressed to 
shape. 

(5) Experience has proved concrete to be a most ex¬ 
cellent fire resisting material. 

(6) Concrete blocks, being hollow, tend to prevent 
sudden changes of temperature within a house, making 
it cool in summer and easily heated in winter. 

(7) The hollow spaces provide an easy means for 
running pipes and electric wires. These spaces may also 
be used wholly or in part for heating and ventilating 
flues. 

Tests of Concrete Fence Posts .—In the summer of 
1904 a number of reinforced concrete fence posts were 
made for experimental purposes, with a view to deter¬ 
mining their adaptability for general use. These posts 
were made both with and without reinforcement, and 
tested at the age of 90 days. The reinforcement, rang¬ 
ing from 0.27 per cent, to 1.13 per cent., consisted of 
four round steel rods, one in each corner of post about 
1 inch from surface, the posts having a uniform cross- 
section of 6 by 6 inches. The posts were molded in a 
horizontal position, as this was found by trial to be more 
satisfactory than molding them vertically. 


HOW TO USE THEM 


371 


The concrete was mixed moderately soft, crushed stone 
between 1 inch and % inch and gravel under % inch 
being used as aggregate. River sand, fairly clean and 
sharp, was employed with Portland cement. The posts 
were tested as beams, supported at both ends and loaded 
at the centre, with spans varying from 4 feet to 5 feet 6 
inches. An attempt was made to prevent slipping by 
providing the reinforcing rods with collars and set 
screws at the ends, but in every case, with but two ex¬ 
ceptions, the rods slipped under a comparatively light 
load, thus showing the necessity for some form of me¬ 
chanical bond. As would be expected, those posts which 
were not reinforced possessed very little strength. 


w 



\rS6 * i ' —SO" -J 


Method of testing 
posts uhder static loads. 


A series of tests was made with sheet-iron reinforce¬ 
ment, in the form of round and square pipes, embedded 
in the posts, but these posts, though developing consid¬ 
erable strength, proved less economical than those rein¬ 
forced with plain rods, and at the same time were less 
simple in construction. The results of these tests, as re¬ 
corded in Table I., do not properly represent the strength 
of similar posts in which some form of mechanical bond 
is provided to develop the full strength of the reinforce¬ 
ment. 






TABLK 1 .— Showing Results of Preliminary Tests of Reinforced Concrete Fence Posts. 


372 


CEMENTS AND CONCRETES 


Equivalent 
Maximum 
Load on 
4-foot 
Cantilever. 

3 1 

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Cio<ooo5nSooon<ooocoohoo<o<ocoo(NOiohodcoooocnt}<o^h^ 
^ CO rH rH C^(NHHHH^ : COHHCOCOCO<O0<O<OiCCOCOCON (M^O H O 6 COH 

O HHHHH H 

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Equivalent 
Load on 
4-foot Can¬ 
tilever at 
First Crack 

°S 

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CiO<005C5MOC5oolO<0(NMOCOiOO •LOHH^C4H(MCCO<Ot^(NOiOCOCi 
s CO H H OlG^C0(NC^Ol(NC^C^C0(MC0 «HHHHHCO(NC^COCOCOiOiOTt<iOTt< 

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Maximum 

Load. 

• 

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§ H <o CO h oco o <o <o 1C ^<o H C^IO iq H W CO H H CO H H o H Oi H 

g rH rH rH rH rH rH rH rH rH rH rH rH rH rH CN of <N CH of rH of of CO CO t*T ci Tf 

Oh 

Load 
at First 
Crack. 

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S COt^OClOOCOCOClHOOOHOO •QOHtO'CCC'lOOOHCOOOOOiO 
5 H <0 CO H O tq H 05 05 00 HO CO N H *00<0<0O<0OOOC^<0'H0qQqQ0OlH 

q rH rH rH rH rH rH rH tH -HHHHH HHC^HHHHHH 

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TABLE 1.—Showing Results of Preliminary Tests of Reinforced Concrete Fence Posts. 

(continued.) 


HOW TO USE THEM 


373 


Equivalent 
Maximum 
Load on 
4-foot 
Cantilever. 

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?COiOOOQCOOOOOOCOCDOOi>NCDC5HHOOHO 
^ 00 O O CH NH 00 00 05 O 00 OO 00 Cl rH 00 lO 05 Cl 

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1,120 

1,120 

1,305 

1,770 

1,646 

1,691 

CD iO <N 
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CDI> CD 

Equivalent 
Load on 
4-foot Can¬ 
tilever at 
First Crack 

• 

X 

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374 


CEMENTS AND CONCRETES 


In order to obtain more data on the subject, this in¬ 
vestigation has been supplemented by a second series of 
tests, the results of which form the subject matter for 
the sections on concrete fence posts and are expressed 
numerically in Table II. 

In these tests it was decided to make the posts taper¬ 
ing in order to economize material and reduce their 
weight. For the concrete, Portland cement, river sand, 
and gravel were used in the proportion l-2y 2 -5, meas¬ 
ured by volume, the gravel being screened below % inch. 
Sufficient water was used in mixing to produce a plastic 
mass, requiring only a moderate degree of tamping to 
bring water to the surface. The posts were molded and 
kept under wet burlap for four weeks, and tested at the 
end of sixty days. The reinforcing members were placed 
in the corners of the posts about 1 inch from the surface, 
being looped and bent, as indicated in Table II. These 
posts were not designed with a view to developing the 
ultimate compressive strength of the concrete, but where 
greater strength is necessary it may be obtained at small 
expense by increasing the percentage of reinforcement. 
It is important that fairly rich concrete should be used 
in all cases to enable the posts to stand exposure and to 
prevent chipping. 

All of these posts measured 6 by 6 inches at the 
bottom and 6 by 3 inches at the top, except Nos. 29, 
30, 31, 32, 33, and 34, which were 6 by 6 at the 
bottom and 3 by 3 at the top. It will be noticed that the 
saving in concrete introduced in the construction of these 
posts is accompanied by a marked decrease in strength 
as compared with the other posts similarly reinforced. 
It would also appear that the twisted wire has a slight 


No, 

1 

2 

3 

4 

37 

38 

9 

10 

11 

39 

40 

13 

15 

16 

17 

18 

19 

21 

22 

23 

24 

25 

26 

27 

28 

29 

30 

31 

32 

33 

34 

35 

36 

6 

7 

8 

14 

20 


HOW TO USE THEM 


375 


3WING THE 

Concrete 


Strength of Reinforced 
Fence Posts. 


Total sectional area of reinforcement. 

In square inches. 

Load at first crack. In Pounds. 

Maximum load. In Pounds. 

Equivalent load on 4-foot cantilever 
at first crack. In Pounds. 

Equivalent maximum load on 4-foot 
cantilever. In Pounds. 

Form of reinforcement. 

0.08 

800 

1120 

218 

306 


1 

.08 

820 

1145 

224 

313 



.08 

640 

1080 

175 

295 


f" . ...> 

.08 

795 

1040 

217 

284 



.08 

940 

1170 

257 

319 



.08 

740 

1075 

202 

293 


I - -- 

.19 

1140 

1280 

311 

349 

] 


.19 

1170 

1885 

319 

515 


. «=—_ 

.19 

1020 

1950 

278 

532 


“- 

.19 

760 

1945 

207 

531 


L,_ 

.19 

820 

1925 

224 

526 


r. -=-- 

.06 

825 

935 

225 

255 



.06 

755 

905 

206 

247 


--> 

.06 

800 

940 

218 

257 


-- 

.06 

815 

935 

222 

255 



.06 

770 

980 

210 

268 


8 r~ -> 

.06 

780 

975 

213 

266 



.13 

1550 

1920 

423 

524 



.13 

1275 

1670 

348 

456 



.13 

1200 

1830 

328 

500 


r 

.13 

1500 

1955 

410 

534 



.06 

980 

980 

268 

268 



.06 

820 

820 

224 

224 



.06 

590 

740 

161 

202 



.06 

745 

745 

203 

203 



.06 

590 

590 

161 

161 



.06 

550 

640 

150 

175 



.06 

560 

635 

153 

173 



.06 

480 

530 

131 

145 



.13 

680 

1040 

186 

284 



.13 

840 

1010 

229 

276 



.13 

1280 

1515 

349 

414 



.13 

800 

1375 

218 

375 



.08 

Tested by impact. 

] 


.19 


do . T 




_ 

.19 


do... 




--■ 

.06 


do ... 



] 


.06 


(in... 




r~— -—> 



























































































































376 


CEMENTS AND CONCRETES 


advantage over the barbed wire as a reinforcing material, 
particularly when two wires are used in each corner of 
the post. 

As stated before, it is impracticable to make a rein¬ 
forced concrete fence post as strong as a wooden post of 
the same size, and this is more especially true if the post 



First method of testing posts, 
by impact. 


NO. 17. 


has to withstand the force of a sudden blow or impact. 
In order to study the behavior of these posts under im¬ 
pact, a number of them were braced, as illustrated in 
No. 17, and subjected to the blow of a 50-pound bag of 
gravel, suspended from above by a 9-foot rope. The 
first blow was delivered by deflecting the bag so as to 
give it a vertical drop of 1 foot, and for each successive 





























HOW TO USE THEM 


377 


blow the drop was increased 1 foot. None of the posts 
showed any signs of failure under the first blow. Posts 
Nos. 14 and 20 cracked under the second blow, and failed 
under the third. Post No. 6 cracked under the second 
blow, which cracked open under the third blow, causing 
a momentary deflection of 5 inches. Posts Nos. 7 and 8 
each developed a crack under the second blow, but 
showed no further signs of weakness after the fifth blow, 



Second method of testing 
posts by impact. 


NO. 18. 


other than a slight opening of the initial crack. In each 
case the only crack developed was at point A. Posts 6, 
7, and 8, which cracked but did not fail undel* the im¬ 
pact test, were further tested, as indicated in No. 18, by 
raising the small end and allowing them to drop from 
successive heights at 1, 2, 3 and 4 feet. Under this test 
a number of cracks developed, but in no case did the re¬ 
inforcement fail. 

Although it might appear from these results that posts 
as here described have hardly enough strength to recom¬ 
mend them for general use, it should be remembered that 
in many cases fence posts are not subjected to impact. 







378 


CEMENTS AND CONCRETES 


and it may prove more economical to replace from time 
to time those which fail in this way than to use wooden 
posts, which, being subject to decay, must all be replaced 
sooner or later. 



NO. 19. 


Retempering. —Table III. illustrates the effect of re¬ 
tempering Portland cement mortar. The mortars used 
consisted of Portland cement and crushed quartzite be¬ 
tween 1 and 2 millimeters in size, mixed in different pro- 




































HOW TO USE THEM 


379 


portions. In each case, after the initial or final set had 
taken place, sufficient water was added in retempering to 


TABLE III.— Effect of Ketempering on Cement Mortars. 


Tensile Strength, in Pounds Per 
Square Inch. 


Treatment of Mortar. 

Neat 

Cement. 

a 

1 Part 
Cement, 
1 Part 
Sand, b 

1 Part, 
Cement, 

2 Parts 
Sand, c 

1 Part 
Cement, 
3 Parts 
Sand, d 

f 

651 

624 

527 

417 

Mortar made up into briquettes . 

650 

701 

493 

385 

immediately after mixing. 

673 

634 

624 

581 

529 

480 

421 

403 

. 

679 

610 

492 

409 

Average ... 

657 

628 

504 

407 

- 

671 

692 

589 

326 

Mortar allowed to take initial 

593 

670 

554 

349 

set, then broken up and made 

644 

654 

559 

330 

into briquettes. 

633 

676 

534 

358 


724 

700 

532 

267 

Average ... 

653 

678 

554 

326 

f 

455 

527 

492 

364 

Mortar allowed to take final 

522 

569 

491 

380 

set, then broken up and 

525 

587 

497 

361 

made into briquettes. 

558 

566 

486 

315 


642 

568 

531 

345 

Average . 

540 

563 

499 

353 


a Initial set, 1 hour 42 minutes; final set, 7 hours 15 minutes. 
b Initial set, 1 hour 30 minutes* final set, 7 hours 15 minutes, 
c Initial set, 2 hours; final set, 7 hours. 
d Initial set, 2 hours 20 minutes; final set, 7 hours. 


restore normal consistency. The briquettes were tested 
at the age of four months. 


















































380 


CEMENTS AND CONCRETES 


Some Practical Notes .—Spencer B. Newbury, who is 
an authority on the subject, says “that the making of 
good cement concrete is a comparatively simple matter, 
and yet, like most simple operations in engineering, there 
is a right way and a wrong way of doing it. Probably 
nine-tenths of the concrete work done falls far short of 
the strength it might develop, owing to the incorrect pro¬ 
portions, use of too much water, and imperfect mixing. 
All authorities are agreed upon the importance of thor¬ 
ough mixing and the use of the minimum quantity of 
water in all classes of concrete work. The matter of cor¬ 
rect proportions of cement, sand, broken stones, etc., is 
one which requires some thought and calculation, and by 
proportioning these ingredients correctly an immense 
saving in cost and increase in strength can easily be se¬ 
cured. 

The chief object in compounding concrete is to pro¬ 
duce a compact mass, as free as possible from pores or 
open spaces; in short, to imitate solid rock as closely as 
possible. Cement is the “essence of rock” in portable 
form, and by its judicious use granular or fragmentary 
materials may be bound together into solid blocks of any 
desired size and shape, which in strength and wearing 
qualities are at least equal to the best stone that comes 
from the quarries. Cement is, how r ever, very costly in 
comparison with the other ingredients of concrete, and 
must not be used wastefully. A little cement, judi¬ 
ciously used, is better than a large quantity thrown in 
recklessly, as a little study of the principles involved 
will plainly show. 

To produce a compact mass from fragmentary ma¬ 
terials, the voids must be filled. Imagine a box holding 1 
cubic foot. If this were filled with spheres of uniform 


HOW TO USE THEM 


381 


size, the voids or open spaces would be one-third the total 
volume, or 33 1-3 per cent., with spheres of various sizes, 
as, for example, from large marble down to fine shot, the 
voids would be much less, and it would theoretically be 
possible, by the use of spheres of graded sizes, from the 
largest down to dust of infinite fineness, to fill the box 
completely, so that there would be no voids whatever. In 
practice it is well known that the use of materials of 
varying fineness gives the best concrete, since the voids 
are much less than in materials composed of pieces of 
uniform size. Hence the common practice of making 
concrete with cement, sand and broken stone, instead of 
with cement and sand, or cement and stone only. The 
sand fills the voids, and if the proportions are correct, a 
practically solid mass results. As an example of this, 
the writer found the briquettes of cement with three 
parts of sand and four parts gravel showed higher ten¬ 
sile strength at 28 days than those made with three parts 
sand only. 

The following table gives the relative weights of a 
given volume of different materials, and also the per¬ 
centage of voids, as determined by the writer. The ma¬ 
terials were shaken down in a liter measure by giving 
one hundred taps on the table, and weighed. In the case 
of the broken stone a larger measure was used. The 
voids were calculated from the specific gravity. 

Comparison of the three different grades of Sandusky 
Bay sand shows how greatly the percentage of voids 
varies with the proportion of fine and coarse grains pres¬ 
ent. The first is the natural sand, not screened, as 
pumped up by the sand sucker from the bottom of the 
bay, and contains a large amount of fine gravel. The 
second is the same, passed through a 20-mesh screen to 


382 


CEMENTS AND CONCRETES 


remove the coarse particles. It will be seen that this 
operation increases the proportion of voids from 32 to 
38 per cent. The third is the same sand passing a 20- 
mesh and retained on a 30-mesh screen, thus brought to 
the fineness of the 4 ‘ standard sand ’ ’ used in cement test¬ 
ing. This shows 40.7 per cent, of voids, owing to the uni¬ 
form size of the grains. The same relation is seen in the 


WEIGHT OF UNIT MEASURE AND PERCENTAGE OF VOIDS IN 
VARIOUS MATERIALS. 



Weight 
of 1 Liter. 

Per Cent 
of 

Voids. 

Portland cement. 

1720 g 


Louisville cement. 


Sandusky Bay sand, not screened. 

1780 g 

32.3 

Sandusky Bay sand, through 20-mesh 

screen .. 

1630 g 

38.5 

Sandusky Bay sand, 20-30 mesh (standard 


sand). 

1570 g 

40.7 

Gravel, % to % inch. 

1510 g 

42.4 

Gravel, % to inch. 

Marblehead broken stone (chiefly about 

1680 g 

35.9 

egg size) . 

1380 g 

47.0 


two grades of gravel given in the table, that containing 
finer grains showing much the lower percentage of voids. 
These figures illustrate the imprudence of screening 
any of the materials used in making concrete. The pres¬ 
ence of clay in sand is, however, objectionable, not be¬ 
cause of its fine state of subdivision, but because the 
clay coats the sand particles and prevents the adhesion 
of the cement. Such sand might be improved by wash¬ 
ing, but probably not by screening. It has been found 


















HOW TO USE THEM 


383 


that cement which has been ground to dust with an equal 
amount of sand goes much further when used for con¬ 
crete than the same quantity of cement when used in 
the ordinary way. This is doubtless owing to the fact 
that the sand dust aids in filling the voids. It is also 
well known that slaked lime, when added to cement mor¬ 
tar, greatly increases the strength of mixtures poor in 
cement. 

From the figures given in the above table the compo¬ 
sition of a theoretically perfect concrete may readily be 
calculated. The existence of voids in the cement may be 
disregarded, since in the process of hardening the cement 
sends out crystals in all directions, completely encrusting 
the sand particles and practically filling all the voids 
which the cement itself contains. Examination of a 
well-hardened briquette of cement with 3 parts sand, 
after breaking, with the aid of a lens, will show this 
clearly 

Suppose, for example, we wish to make the best pos¬ 
sible concrete from Portland cement with the sand and 
gravel given in the above table. We should, of course, 
choose the unscreened sand and gravel as containing 
the least proportion of voids. One hundred measures of 
gravel would require 35.9 measures of sand. As the 
sand contains 32.3 per cent, of voids, we require 32.3 
per cent, of 35.9, or 11.6 measures of cement. The pro¬ 
portions would, therefore, be: Cement, 11; sand, 3, and 
gravel, 9. It is customary, however, to increase the pro¬ 
portion of mortar (cement and sand) by about 15 or 20 
per cent., in order that the coarser materials may be 
completely coated with the finer mixture. Making this 
addition, we find the concrete proportions to be: Cement, 
1; sand, 2.8; gravel, 7. Allowance must also be made in 


384 


CEMENTS AND CONCRETES 


practice for imperfect mixing, since the materials can 
never be distributed in a perfectly uniform manner. 
Practically, with these materials, a concrete of cement 
1, sand 2%, and gravel 6, would probably give the best 
result, and little or no improvement would result from 
increasing the proportion of cement. 

A similar calculation shows that the correct propor¬ 
tions for a concrete made of the sand and broken stone 
given in the table would be 1 to 3 to 6%. Increasing 
the amount of cement and sand by 20 per cent., we have 
1 to 3 to 5y 2 . Probably 1 to 2 y 2 to 5 would be found to 
give the best results in practice. The determination of 
the voids in the sand, gravel and broken stone used is 
of the greatest value in adjusting the proportions of 
concrete. 

The simplest method of determining this in the case of 
gravel and broken stone is to have a metal box made of 
1 cubic foot capacity; this is filled with the material to 
be tested, well shaken down and struck off level. The 
box and contents are then weighed. Water is now 
poured in until it rises even with the surface, and the 
total weight again taken. The difference in the weights 
is the weight of the water filling the voids of the ma¬ 
terial. Now 1 cubic foot of water weighs 64 4-10 lbs., 
and from the weight of the water found the percentage 
of voids can be simply calculated. For example, in one 
experiment the box and broken stone weighed 88 lbs. 
After filling the spaces in the stone with water the 
weight was 117% lbs., a difference of 29% lbs. The 
percentage of voids is, therefore, 29%xl00 divided by 
62.4 equals 47 per cent. 

In the case of sand this method will not answer, as it 
is difficult to completely fill the voids of the sand by 


HOW TO USE THEM 


385 


adding the water. The voids can, however, be readily 
calculated from the weight of a cubic foot and the spe¬ 
cific gravity. The specific gravity of quartz sand is 
about 2.65. A cubic foot of sand, free from voids, would 
therefore weigh 2.65x62.4 equaling 165.4 lbs. The 
weight of a cubic foot of sand, well shaken down, was, 
however, found to be only 112 lbs., a difference of 53.4 
lbs. The proportion of voids was, therefore, 53.4x100 
divided by 165.4 equals 32.3 per cent. The percentage 
in voids in clean natural sand does not vary greatly, and 
may be taken as 33 to 35 per cent, for coarse and 35 to 
38 per cent, for fine sand. 

We have already seen that with the materials above 
described, concrete composed of 

Cement 1, sand 2y 2 , gravel 6, or 

Cement 1, sand 2 y 2 , broken stone 5 
by measure, will be practically compact and non-porous, 
and that there is no object in increasing the proportion of 
cement. Such concrete, if made from Portland cement, 
will, however, be rather expensive, requiring about one 
barrel of cement (equals 3 y 2 cubic feet) for every cubic 
yard. This is unnecessarily good for ordinary work, and 
will only be required for foundations of engines and 
other heavy machinery, in which the best possible result 
must be secured regardless of cost. In cheaper concretes 
the relative proportions of sand and broken stone should 
be the same, as determined by the voids in the coarser 
materials, while the proportion of cement may be varied 
according to the required conditions of quality and cost. 
Most excellent concrete may be made by using: 

Portland cement 1, sand 7, stone or gravel 14. 

Here are specimens of these two concretes, taken from 
trial blocks laid Oct. 1, 1894, to determine the best pro- 


386 


CEMENTS AND CONCRETES 


portion for the foundation of brick pavement. The 
richer of the two, 1-5-10, is certainly good enough for 
any purpose, even for engine foundations. A cubic yard 
of such concrete requires about % barrel of cement; the 
total cost of the cement, sand and stone is about two 
dollars per cubic yard. This is no more expensive than 
concrete made from Louisville cement with 2 of sand 
and 4 of broken stone, and is immensely superior to the 
latter in strength. 

The following table shows the results obtained in 
Germany by R. Dykerhoff in determining the crushing 
strength of various concretes. The blocks used were 2% 
inches square, and were tested after one day in air and 
27 days in water. 


Proportions by Measure. 

Strength under Compression. 
Pounds per Square Inch. 

Portland 

Cement. 

Sand. 

Gravel. 

1 

2 


2125 

1 

2 

3 

2747 

1 

2 

5 

2387 

1 


5 

978 

1 

3 

.. 

1383 

1 

3 

5 

1632 

1 

3 

6X 

1515 

1 

4 


1053 

1 

4 

5 

1273 

1 

4 

8X 

1204 


These figures prove the statement already made, that 
mixtures of cement and sand are strengthened, rather 
than weakened, by the addition of a suitable quantity 
of gravel. It will be noticed that the mixture—cement 1, 










HOW TO USE THEM 


387 


sand 2, gravel 5—is actually stronger than cement 1, 
sand 2, without gravel. The same is shown in the mix¬ 
tures 1 to 3 and 1 to 4. 

In estimating the amount of material required to pro¬ 
duce a given volume of concrete, it may be stated that 
when very strongly rammed into place the volume of 
concrete obtained from correct proportions of the ma¬ 
terials will be about 10 per cent, more the volume 1 cubic 
foot cement, 2 y 2 cubic feet sand, and 5 cubic feet stone, 
and will therefore yield about 5% cubic feet concrete. 

Another Concrete Stairway and Steps .—A good stair¬ 
case is one of the essential features in a building. The 
safety and convenience of persons using a staircase are 
not only affected by the due proportions and arrange¬ 
ments of the steps, but by the strength and fire-resisting 
properties of the materials employed, and the manner of 
construction. The wells are in many cases too small, 
out of proportion to the structure, which necessitates 
dangerous winders, tiring high risers, narrow treads, or 
insufficient headway. Some architects when designing a 
staircase pay little attention to the practicability of con¬ 
struction. What may seem easy in theory or on paper 
is often found impracticable or unnecessarily difficult 
when reduced to actual practice. The errors of omission 
and commission are left for the workmen to contend 
with and overcome as best they may at the employer’s 
expense. Happily such cases are few, the majority of 
architects supplying figured drawings, which are not 
only a help and guide to the workmen, but also ensure 
a practical staircase in due proportion and without un¬ 
necessary expense. Staircases should be spacious, light, 
and easy of ascent. It is generally admitted that a 12 
inch tread and a 6 inch rise is the most convenient, and 


388 


CEMENTS AND CONCRETES 


that no tread should be less than 8 inches or more than 
16 inches, and no rise less than 4^ inches and more than 
7 inches. According to Blondel, the rise should be re¬ 
duced 1/2 inch for every inch added to the tread, or the 
tread reduced by 1 inch to every % inch added to the 
riser, taking a 12 inch tread and a 6 inch rise as the 
standard. Treads may be increased by means of a nos¬ 
ing, which usually projects from 1 inch to l 1 ^ inches. 
Nosing not only gives more available space for the tread, 
but also affords some advantage to persons going down 
stairs, as the heel cannot strike against the rising. In 
setting out a flight of stairs, the tread of the steps are 
measured from riser to riser. Where practicable, the 
number of steps from landing to landing should be odd, 
because when a person begins to ascend with the right 
foot first (as most people do) he should end with the 
same foot. Rectangular steps are called fliers. Wind¬ 
ers, being narrowed at one end, are always more in¬ 
convenient and dangerous than straight steps, and 
should not be used for public buildings or other places 
where there is a crowded traffic. Winders are also 
more expensive to construct. They are, however, un¬ 
avoidable in circular staircases, also in some instances 
in angles, where a quarter or half space landing would 
not give the desired rise. Winders should be so made 
that the tread 6 inches from the end of the narrow 
point should be wide enough to step upon without dan¬ 
ger of slipping. No stairs should be less than three 
feet from the wall to the hand-rail. A width of 3 feet 
6 inches will allow two persons to walk arm in arm up or 
down stairs. A width of 4 feet6inches is generally used; 
this gives plenty of space for two persons to pass each 
other. No hard and fast rules can be laid down for the 


HOW TO USE THEM 


389 


size of treads and risers, as they are regulated more 
or less by the size of the well and the height from floor 
to floor. Too few steps in a flight are as bad as too 
many. There should not be less than three. Long 
straight flights of steps are tiring and dangerous. The 
straight line of length should be broken by landings, 
so that there may not be more than eleven continuous 
steps. Landings give ease in ascending and safety 
when descending. No landing should be less in length 
than the width of the staircase. The staircases in the 
pre-Elizabethan style were usually plain, dark and in 
long narrow flights; but with the Elizabethan archi¬ 
tecture came in a more commodious, light and decora¬ 
tive style. Wood stairs are often enriched with plaster 
work, the soffits being panelled with plaster, and the 
strings adorned with composition or plaster enrich¬ 
ments. Stone stairs are also frequently enriched with 
plaster mouldings in the angles of the soffits and walls. 
External steps and landings are usually made with a 
fall of % inch to the foot to allow rain to fall off. 

Cast Concrete Stairs .—Concrete is now fast super¬ 
seding stone, wood and iron for staircase construction, 
where strength, durability and economy and fire-resist¬ 
ing properties are required. Cast concrete stairs were 
first introduced nearly sixty years ago. The stairs 
were cast in single steps, or in treads or risers, and 
fixed in the same way as natural stone. Square and 
spandrel steps, risers and treads are cast in wood 
moulds; circular steps and curtails in plaster moulds. 
Spandrel steps should have the wall or “tail” end 
formed square, and about 4% inches deep, to give a 
better bed and bond in the wall. A good mixture is 3 
parts of granite or slag chippings and 1 of Portland 


390 


CEMENTS AND CONCRETES 


cement, ganged stiff, and well rammed into the moulds. 
When set they are removed from the moulds, air dried, 
and placed in water or a silicate bath, and treaded in 
a similar way to that described for slabs. For long 
steps pieces of T iron, or iron pipes, are sometimes in¬ 
serted in the centre of the concrete while being cast. 
The iron is not actually required to strengthen con¬ 
crete properly made, but is used to give a temporary 
strength to the cast while it is green, so as to allow 
more freedom and security in handling the cast when 
it is being taken from the mould and moved about till 
permanently fixed. Landings are cast in a similar way, 
but unless very small, they are best done in situ. I 
have made landings up to 40 feet superficial, but owing 
to the cost of transit, hoisting and fixing they were 
not profitable. 

Tests of Steps .—The following examples show the 
strength of concrete steps: In Germany, when con¬ 
structing a concrete stair, with square steps 3 feet 4 
inches long, and 6-inch tread, and 6y 2 -inch rise, and 
one end set 8 inches into the walls, four steps were sub¬ 
mitted for trial, and 5,940 lbs. weight of iron were 
gradually piled on them. The steps showed no signs 
of fracture, but no more weight could be put on be¬ 
cause the masonry began to yield. The load was left 
on three days, and the steps remained unaffected. Al¬ 
though numerous tests have been made of concrete 
floors and blocks, few have been made for concrete 
steps. The following may be given as a reliable one: 
The steps were about 6 feet long, 11-inch tread and 
6-inch rise. Every step was tested in the presence of 
the foreman concreter and author. The steps were 
supported at both ends, and weighed with a distribu- 


HOW TO USE THEM 


391 


tive load. The majority, which were matured by age, 
passed the specification standard. 

Concrete Stairs Formed “in Situ .”—Concrete stairs 
are an outcome of stairs built with cast concrete steps. 
Stairs formed in situ were introduced in 1867. The 
idea was suggested by the use of reverse moulds for 
fibrous plaster work, and in the formation of concrete 
dormer windows made in situ on some mansions. The 
step landings and the wall bond, being a monolith 
structure, were to a certain degree self-supporting. 
They tend to strengthen instead of to weaken the 
walls. Architects generally supply drawings of the 
intended staircase, hut as there is often a differ¬ 
ence in the size of the details of the actual work and 
the drawings, it is necessary that the workman should 
have a practical knowledge of setting out the “height’’ 
and “ go ” for the pitch board, to suit the landings and 
the well of the staircase, and ensure the necessary head- 
room. 

Setting Out Stairs .—A correct method of setting out 
the framing for concrete stairs is of primary import¬ 
ance. The height of a stair is the length of a per¬ 
pendicular line drawn from the upper of a floor to 
that of the one immediately above it. The “go” is 
the length of a horizontal line drawn along the centre 
line of the flight of steps or stair space. The exact 
height and widths should be taken on a rod, which 
should afterwards be used for setting out the work. 
Never work without this rod, as it is quicker and more 
accurate than measuring with a 2-foot rule. There are 
various ways of getting the dimensions of treads and 
rises. The following is a simple one and answers for most 
purposes. The height and go are taken and suitably 


392 


CEMENTS AND CONCRETES 


divided. For example, if the height from floor line to 
floor line is 9 feet 3 inches, and it is proposed to 
make each rise 6 inches high, reduce the weight to 
inches, which would he 111; divide by the proposed 
height of each step—6 inches—the quotient will be 18, 
giving the same quotient 6 and 3-18. If there are 
intermediate landings, or half spaces, their dimensions 
must be allowed for. The size of the tread is obtained 
by dividing the “go” by the number of steps. The 
quotient will be the width of the tread. Great care 
should be taken in setting out the rods and pitch 
boards. It is better to measure thrice than to cut twice. 
When the string line is marked on the wall, a chase 
about 4% inches deep is cut into the wall. It is not 
necessary to cut the chase straight at the soffit line, as 
it is apt to cut into a half, or rather a whole brick, 
and leave the ends loose. The irregular line of chase 
below the soffit line can be made solid during the pro¬ 
cess of filling in the steps. The chase should be cut 
as the work proceeds. Not more than one flight at a 
time should be cut, to avoid weakening the wall. In 
some instances a brick course in sand is left by the 
bricklayers. The bricks are then taken out as the 
work proceeds. 

Nosings and Risers .—Nosing mouldings should be 
strong and bold. A simple but well-defined moulding 
not only gives greater strength, but is more in keep¬ 
ing with its purpose than one with numerous or small 
members. Nosing and riser moulds are best formed 
in two parts, the nosing moulds being one part and the 
riser board the other. To cut them out of the solid 
would not only be expensive, but also cumbrous to fix. 
They can be run at most saw and moulding mills. 


HOW TO USE THEM 


393 


They should be run in lengths and then cut and mitred 
on the job. Illustration No. 20 shows various forms 
of nosing. Pig. 1 is a simple nosing for common work. 
Pig. 2 may be used for school stairs, etc. Pigs. 3 and 
4 are well adapted for a good class of work. It will be 
seen that the lower edges of the riser boards are 
splayed. This is to admit the shoe of the running 
mould; also a trowel to work close up to face of the 


Fi& i. 



Fig. 1. Fig. 3. Fig. 4 . 



Sections or Nosing 
TVIoulds with Riser Boards. 


NO. 20. 


concrete riser when running and trowelling off the 
treads. The dotted lines indicate the line of tread. 
Nosing moulds are cut in the centre of the section, and 
afterwards the two parts are held in position with 
screws while the steps are being filled in. This allows 
the upper part to be unscrewed and taken off when the 
stuff is nearly set, thus allowing more freedom to 
trowel the surface of the tread; also to make a better 
joint while the stuff is green, and at the part that is 
cast and the part to be trowelled. The joint in the 
nosing mould leaves a thin seam which is easily cleaned 
off, whereas the joint of the tread and nosing is not 
only seen more, but is also more difficult to make good. 










394 


CEMENTS AND CONCRETES 


Illustration No. 21 shows the mould and joint and 
screws for fixing same. 

Framing Staircases .—The wood framing for con¬ 
crete stairs differs from and is partly the reverse to 
that used for wood stairs. The nosings are formed the 
reverse of the moulding, and the whole framing is so 
constructed that it forms a mould to cast all the steps 
and landings, from floor, in monolithic form, or one 
piece. When the positions of half spaces or other 



Jointed Nosing Mould 
wrrH Kiser Board, 
no. 21. 

landings are set out on the walls, strong planks are 
fixed on edges so as to give fixing joints for the car^ 
riage and outer strings. The strings are then fixed 
to act as guides for fixing the centring, risers and nos¬ 
ing moulds. Where practicable, the outer string should 
be so arranged in the fixing that it can be taken off 
after the concrete is firm without disturbing the cen¬ 
tring. This allows the returned ends of the steps to 
be cleared off while the work is green. The carriage 
boards are fixed from landing to landing. Illustra¬ 
tion No. 22 shows the forms and positions of the vari- 













































































































































































396 


CEMENTS AND CONCRETES 


ous parts, with their names. Bullnoses or curtails and 
circular parts of nosings are formed in plaster moulds, 
which are run with several reverse running moulds. 

Staircases between walls are more simple than open 
staircases; therefore they are more easy to frame up. 
The string boards are cut to the reverse of that used 
for wood stairs. A string is cut for each wall. The 
riser boards are then fixed to the wall strings. The 
centring for the soffits is fixed independently, the 
boards being laid on fillets which are nailed on each 
wall. For short flights of steps or common stairs, such 
as for cellars, etc., string boards may be dispensed with. 
The positions and sizes of the risers, treads, soffits and 
landings are first set out and marked on the walls. 
Riser fillets are then nailed on the walls, taking care 
to keep each fillet in a line with the riser mark, and 
to allow for the thickness of the riser boards which 
are subsequently nailed on the inner sides of the fillets. 
Riser boards for winders are generally hung on long 
fillets and then nailed on the walls. Long fillets ex¬ 
tending upwards enable the work to be easier and more 
strongly fixed, as they cover more brick joints than if 
cut to the exact height of the riser. 

Centring for Landings and Soffits .—Centring for* 
landings and the soffits of stairs should be made strong 
and true. The timber should be well seasoned, to pre¬ 
vent warping or shrinkage. The outer angles of land¬ 
ings should be supported by strong wood props, not 
only to carry another prop for the landing above. All 
centrings should be made perfectly rigid, to stand the 
weight of the concrete and the ramming. Great care 
should be taken that the timber framing is securely 
supported, as any deflection will not only throw the 


HOW TO USE THEM 


397 


work out of level, but will also tend to crack the con¬ 
crete. The principal props should be cut about % 
inch shorter than the exact height. They are placed 
on a solid bed, the %-inch space at top being made 
up with two wedges, the thin ends being inserted in 
opposite directions and gently driven home from each 
side until the exact height is obtained. If it is dif¬ 
ficult to get the top of the prop, the wedges can be 
inserted at the bottom. The use of the wedges will 
be seen when the centring is struck. If there are 
winders in the stairs, the centring for the soffit will be 
more or less circle on circle. This form of centring 
is done by lathing, with 1-inch boards, cut to a taper, 
the surface being made fair with a gauged lime and 
hair. Rough 1%-inch boards are used for the centring. 
This should be close-jointed. Open joints or sappy 
timber act as a sieve, and allow liquid cement to drip 
through, thus robbing the concrete of its strength. 

Waterproof Centring —The following is a method 
that has been used with marked success for the sof¬ 
fits of stairs, landings and the ceilings of floors. The 
initial cost of preparing is small, and is repaid with 
interest by the- decreased cost of setting and the in¬ 
creased strength and solidity. For ordinary work, 
such as warehouses, etc., it is very suitable, as a fin¬ 
ished surface is formed, and no setting required. It 
seems strange that, when casting concrete work out of 
a wood or a plaster mould, the mould is seasoned, and 
every precaution taken, not only to stop suction, but 
also to prevent the escape of liquid cement; but when 
casting a large surface in situ (where every precau¬ 
tion should be taken to obtain the maximum of 
strength), any kind of centring (which is a mould) 


398 


CEMENTS AND CONCRETES 


is thought good enough, if only sufficiently strong to 
carry the concrete till set. I am aware that many 
workers in concrete think that an open or porous 
centring is a benefit instead of a defect, simply be¬ 
cause it affords an escape for excess of water. But 
why have excess of water at all? There is no gain 
in time or strength, but a direct loss in both points. 
The excess water descends through the concrete by 
force of direct gravitation, and always carries a cer¬ 
tain amount of liquid cement with it to the centring, 
leaving the aggregate more or less bare, and the body 
of the concrete weak. A part of the liquid cement 
also oozes through the joints and crevices, which leaves 
the skin of the concrete bare and broken. There is 
no reason or excuse for excess water, and it is simply 
the result of ignorant or careless gauging, which is not 
only a waste of time, water and cement, but a loss in 
the ultimate strength, and the cause of cracks. Porous 
centring is also a dirty process. The overhead drip, 
drip, is neither good for the workmen nor the material 
underneath. 

The process of forming the rough centring boards 
watertight is simple and expeditious, being done by 
laying the rough board surface with a thin coat of 
gauged plaster; and when the centring has been struck 
the plaster will come with the boards, leaving the con¬ 
crete with a fair face. The ramming forces a certain 
amount of water to the lower surface or centring, and 
this is so close and fine that it takes an exact impress 
of it; consequently the truer and smoother the centring 
the truer and smoother the concrete surface. The film 
of water indurates the skin of the concrete and prevents 
surface or water cracks. It will be noticed when filling 


HOW TO USE THEM 


399 


in dry or porous plaster moulds that the concrete cast 
produced has a surface either friable when newly cast, 
or when dry the surface is full of small water lines, 
like a map, or a broken spider’s web. This is owing 
to the suction caused by the porous nature of the mould 
and the water escaping through the weak or open parts 
leaving corresponding lines on the concrete surface. 
These defects are obviated by using waterproof cen¬ 
tring. 

Where fineness of finish is not required, such as ware¬ 
house floors, the surface can he made sufficiently fair 
and smooth when filling in the concrete without sub¬ 
sequent setting. The plaster is laid on the centring, 
and made fair and smooth, and then the surface is 
saturated with water to correct the suction; or the 
surface, if dry, may be brushed over with a thin soap 
solution to prevent adhesion. On this surface a coat 
of neat cement about % inch is laid, and on this the 
concrete is placed. The two unite in one body, and 
when set, and the centring struck, the plaster sheet 
comes with the boards, leaving a smooth surface. This 
surface can be made in color by lime washing, which 
will also give more light, or a finished white surface 
can be obtained by substituting parian or other white 
cement for the neat Portland cement. The concrete 
must not be laid until the white cement is firm, not set, 
otherwise the concrete will force its way in thin or 
soft parts and disfigure the surface. I have success¬ 
fully used this method for obtaining a finished sur¬ 
face when encasing iron girders with concrete for fire¬ 
proof purposes. 

Staircase Materials .—With regard to the materials 
for a concrete staircase, no one who intends to con- 


400 


CEMENTS AND CONCRETES 


struct them substantially, fireproof and economically, 
can afford to use common substances, when by judi¬ 
cious selection and for a trifling additional first cost a 
combination of materials can be obtained, which, if 
not (strictly speaking) fireproof, is at least the most 
incombustible constructive compound known. This is 
a quality of the most vital importance in modern house 
construction. Portland cement and slag cement are 
the best known matrices. The finer Portland cement 
is ground, the greater its heat-resisting powers. Slag 
cement is lighter than Portland cement, and its fire- 
resisting properties exceed those of both gypsum and 
Portland cement. But as its manufacture is as yet 
somewhat limited, and its strength not uniform, ex¬ 
ceptional care must be exercised in testing its general 
qualities before using it for staircases. Broken slag, 
firebricks, clinkers and pottery ware are the best ag¬ 
gregates, being practically fireproof. All should be 
clean, and in various graduating sizes, from that of a 
pin’s head to that of a walnut, for roughing out with. 
The topping should be the same as that described for 
Eureka paving. 

Filling in Stairs .—Before gauging the materials, 
sweep out all dust in the interior of the framing and 
the wall chase and then wet the latter, and oil the 
woodwork. If the wood of the nosing moulds and 
risers is sappy or open grained, the long lengths, be¬ 
fore being cut and fixed, should be made smooth and 
indurated by coating with a solution of hot paraffin 
wax. The smoother and less absorbent the surface of 
the wood, the more readily and cleaner will the mould 
leave the cast work. Paraffin also renders the wood 
damp-proof, thus preventing swelling or warping. For 


HOW TO USE THEM 


401 


ordinary purposes one or two coats of paraffin oil will 
be found sufficient. This should be done two or three 
hours before the steps are filled in, so as to allow the 
oil to partly dry in and stop the pores of the wood. 
If the wood absorbs all the oil, and has a dry sur¬ 
face, brush the surface again with paraffin, using a 
semi-dry brush. This should be done as the work pro¬ 
ceeds. If the surface is over wet, the oil mixes with 
the cement, thus causing a more or less rough sur¬ 
face. Soap solution may be safely used for rough 
concrete, or where a rough surface is left to be sub¬ 
sequently set. In the latter case the surface must be 
well wetted with water and scrubbed before the final 
coat is applied. Soap solution may also be used for 
rough framing, such as soffit boards, but soap should 
not be used for fine concrete or a finished surface, 
as it leaves a film of grease which has a tendency to 
prevent the cement adhering when clearing up or mak¬ 
ing good the finished surface. As the work of filling 
proceeds, the surface should be brushed over with a 
slip, that is, neat cement, to fill up all angles, and 
obtain a surface free from “bulbs” and ragged ar¬ 
rises. 

The coarse concrete for roughing out the stairs is 
composed of 1 part of Portland cement and 3 parts of 
coarse fireproof aggregate. These materials must be 
gauged stiff and laid in small portions of about a pail¬ 
ful at a time, taking care to thoroughly consolidate 
by ramming and beating with a wooden mallet, using 
a wooden punner or punch to get into the angles and 
deep parts. When the first layer, which may be about 
3 inches thick, is rammed, another layer is deposited 
and rammed, and so on until the rough stuff is within 


402 


CEMENTS AND CONCRETES 


y 2 inch of the line of tread. It must not be omitted to 
brush the strings, treads and nosing moulds with slip 
as the work proceeds. This is most effectually done 
by the aid of a tool-brush. Care must be exercised 
when ramming stairs with mallets or punches that the 
mallet or other implement used is not too large or too 
heavy, for it would most likely cause the framing to 
bulge out, and the form of the work would be irre¬ 
trievably spoilt. During the operation of ramming 
some of the water and a part of the constituent of the 
cement is forced upwards, and leaves a thin, smooth, 
clayey film on the surface, which prevents the adhesion 
of the next layer. For this reason the successive lay¬ 
ers should be deposited before the previous one is set, 
and the topping should be laid while the coarse con¬ 
crete is yet green. Too much stress cannot be laid upon 
the importance of topping the rough coat while it is 
green. This is one of the secrets of success of solid 
and strong work, so no more rough stuff should be laid 
than can be topped before the rough is set. 

The fine stuff for the topping is the same as for 
Eureka paving, viz., 1 part of cement to 2 parts of fine 
aggregate, gauged firm and plastic. The tread is made 
level and fair by means of a running mould so formed 
that it bears on the nosing moulds above and below the 
tread. The mould has a metal plate or “shoe” fixed 
so as to run and form the tread. The shoe projects 
so that it will work under the riser board close up to 
the concrete riser. Illustration No. 23 shows a sec¬ 
tion of steps with the mould in position; also a sec¬ 
tion of the nosing mould and soffit boards and car¬ 
riage. The end of the slipper next to the wall is cut 
short to allow the mould to run close up to the wall. A 


HOW TO USE THEM 


403 


section of a T iron is shown as sometimes used as an in¬ 
ternal support. Iron is used for long steps, or where 
stairs are intended for heavy traffic. Iron helps to sup- 



And Noser Mould, with Concrete and Tread Run¬ 
ning Mould in Position. 

NO. 28. 

port the concrete until set; it is placed in alternate 
steps, or in every third or fourth step, according to the 
length of step. Ordinary sized steps require no iron, 


























404 


CEMENTS AND CONCRETES 


unless as a support for the concrete while green, and 
during the process of making. 

Finishing Stairs .—When the treads are firm after 
being run, the upper part of the nosing moulds are 
removed, the surface and joists trowelled off. The ad¬ 
vantages of having the nosing mould in two parts will 
thus be seen, as it allows the joint at this most notice¬ 
able part to be neatly cleaned off while the work is 
green. The lower part of the mould will support the 
concrete nosing during the finishing of the tread and 
until the concrete is set. If the work is done with a 
nosing mould in one piece, which necessitates its being 
left on until the concrete is set, the joint has then to be 
filed down and stopped, and however well done, has a 
patchy appearance. When the treads are finished, and 
the work set, but not dry, the riser and string boards 
are taken off, the joints made good, and the returned 
end of the steps cleaned off. If the stuff has been 
properly gauged and rammed, there should be little 
or no making good required, but it is important that 
if necessary it should be done while the work is “green. 
A thin layer of neat cement will not adhere on a dense 
and dry body of concrete. The only way to obtain 
perfect cohesion is to cut the damaged surface out to 
a depth of not less than % inch, then thoroughly wet 
it, brush the surface with liquid cement, and fill it in 
with gauged cement. No traffic should be allowed on 
the treads during the process of setting and harden¬ 
ing. The work is further protected and hardened by 
covering with sacks kept wet for several days by fre¬ 
quent watering. Where there are several flights of 
stairs to construct, there should not be less than three 
sets of strings and riser boards, which will enable the 


HOW TO USE THEM 


405 


carpenter to fix one set while the plasterers are filling 
in and cleaning off the others. 

N on-Slippery Steps .—Incessant traffic tends to make 
the treads of steps more or less slippery. In order to 
obviate this, the surface is indented with a concrete 
roller, similar to that used for some kinds of paving. 
Another way is to form three or four Y-shaped grooves 
from 1 inch to 2 inches apart on the treads while the 
concrete is moist. Another way is to insert leaden 
cubes about 1 inch square from 2 to 3 inches apart 
in the surface of the treads. Well-seasoned, hard 
wooden blocks, about the same size as the lead and 
fixed in a similar way, keeping the end grain vertical, 
are also used for this purpose. India rubber and cork 
cubes may also be used. 

Striking Centrings .—This should not be attempted 
until all the other work, with the exception of finishing 
the soffits, is done. It will be understood that the 
framing can be arranged so that the string and riser 
boards can be taken off without disturbing the soffit 
centring, which is kept up as long as possible. The 
time for striking centring greatly depends upon the 
class of cement used, the manner of gauging and lay¬ 
ing the concrete, and the temperature; but generally 
speaking, centring should not be struck for at least 
ten days. A stair between the walls can be struck 
much sooner than one having only one bearing by which 
its own weight is carried. I have seen a stair, with 
steps projecting 3 feet 6 inches from the wall, cleared 
of all supports in five days from the time of filling 
in; but this was with good cement, gauged 1 part to 2 
of aggregate, and in warm weather, and the stair was 
strengthened with T iron. 


406 


CEMENTS AND CONCRETES 


The centring and framing for a flight of stairs should, 
where practicable, be independent of other stairs above 
or below, so that they can be struck in due rotation. 
The wedges of the main props should be gradually 
withdrawn. This tends to avoid the sudden jar which 
otherwise often happens when the centring is too sud¬ 
denly struck. The sudden removal of centring and 
the inflexible nature of concrete are the cause of body 
cracks. The damage caused by the sudden jar may 
not be seen at the time, but it will be eventually devel¬ 
oped by the force of expansion, which always finds out 
the weak spots. 

Concrete and Iron .—Iron pipes, bars and T pieces 
are sometimes used with concrete stairs where the steps 
are long, or where landings have little support from 
walls. They help to carry the dead weight until the 
mass is thoroughly set, and also prevent sudden de¬ 
flection if the centring is struck too soon. When iron 
pipes are used for steps they should go right into the 
wall chase. Iron T pieces are used for long landings. 
Care must be taken that, if the iron is used, no part 
should be left exposed. It must be embedded in the 
concrete to protect it from oxidization and the effects 
of fire. When iron girders, etc., are partly exposed, 
they should be painted. Iron bars or pipes are occa¬ 
sionally used to strengthen the outer strings of spandrel 
stairs. The iron is laid in the moist concrete 
near and along the string, having the ends projecting 
into the walls or landings. Angle irons are often used 
for unsupported concrete angles. Iron pipes, bars or 
joists are used as integral supports for landings and 
floors having unsupported ends. 

The tensile strength of bar iron is materially in- 


HOW TO USE THEM 


407 


creased by twisting. A bar y 2 inch square with three 
twists per foot will gain about 50 per cent, in tensile 
strength when embedded in concrete, and give a corre¬ 
sponding strength to the concrete. A combination of 
iron and concrete is of special service where space is 
limited. For instance, if a beam or landing requires 
a certain thickness to carry a given weight, and it is 
inconvenient or difficult to obtain that thickness, the 
requisite degree of strength with a reduced thickness 
may be obtained by the combination of both materials. 
This gives the combined iron and concrete a useful ad¬ 
vantage over stone. It is important to secure the full 
strength of the iron, and that none be lost or neutral¬ 
ized. In order to obtain the full strength the iron 
should be judiciously placed. Thus, a piece of iron 
surrounded by twenty times its sectional area of con¬ 
crete would increase the weight-sustaining power of the 
iron in the centre and would have its strength in¬ 
creased about twice. If the same quantity of iron was 
placed in several pieces, so as to throw as much tensile 
strain on the iron as possible, the strength would be 
increased nearly four times. In order that none of the 
strength be lost or neutralized, the iron should be 
placed near the lower surface; if fixed higher, they are 
nearer the axis of neutral stress, and are correspond¬ 
ingly less effective. The use of iron in concrete is in¬ 
valuable for many constructive purposes, but for gen¬ 
eral work, unless as a temporary aid and in a few ex¬ 
ceptional cases, it is unnecessary. For all other things 
being equal, the huge board of reserve strength in good 
concrete is alone sufficient to sustain as great if not 
a greater weight than that sustained by natural stone. 
No other artificial compound exceeds the strength of the 


408 


CEMENTS AND CONCRETES 


natural substance, as does artificial stone composed of 
Portland cement concrete. 

Setting Concrete Soffits .—The soffits of stairs and 
landings, if neat cement has been used on a water¬ 
proof centring, as already described, only require a lit¬ 
tle stopping and coloring, but for work done on rough 
centring a setting coat has to be laid. This is usually 
done with neat Portland cement, though it is frequently 
gauged with lime putty to make it work more freely. 
The surface should be well roughened and wetted, to 
give a key and obtain perfect cohesion. It requires 
great care and time to make a good and true surface 
with Portland cement on a body of concrete, espe¬ 
cially if the concrete is dry, which is generally the 
case where there are several flights of steps in a stair¬ 
case, and the setting of the soffits and landings are 
left to the last part of the work. I have obtained 
equally good results by using Parian or other white 
cements for setting the soffits of staircases. When 
using white cements for this purpose it is better to 
brush the concrete surface with liquid cement before 
laying the gauged cement. The laying trowel should 
follow the brush, or at least before the liquid cement 
dries in. This not only secures better cohesion, but 
tends to prevent the setting coat peeling when trowel¬ 
ling it off. Soffits are sometimes set with gauged put¬ 
ty. This is like putting a beggar on horseback, and 
the work is never. satisfactory. 

Fibrous Concrete .—As already mentioned, canvas 
and other fibrous materials may be advantageously 
used with Portland cement for several purposes. Can¬ 
vas forms a good ground for a setting coat on concrete 
surfaces. It gives a uniform and strong key, prevents 


HOW TO USE THEM 


409 


surface cracks, and the final coat from peeling. Coarse 
canvas cut to convenient sizes is used. It is laid on 
the centring, and held in position with tacks, or with 
the same kind of cement as intended for the final coat. 
The canvas is then brushed with liquid cement, and 
then the concrete is laid while the canvas is moist, so 
that the whole will form one compact body. When the 
centring is struck, the fibrous concrete surface is rough¬ 
ened with a sharp and fine drag, so as to raise the 
fibre of the canvas, thus giving a fine, regular and 
strong key. This surface requires less material for the 
final coat than the ordinary concrete surface. If tacks 
are used they must be extracted before the final coat is 
laid, to avoid discoloration. The rough concrete and 
the white surface coat may also be done in one opera¬ 
tion. The centring is made fair and smooth, and then 
oiled with chalk oil. The white cement is gauged stiff 
and laid on the centring. Coarse canvas is then laid 
on and well brushed with liquid cement. When this 
is firm (but not set) the surface is again brushed, 
and then the concrete is laid. The concrete is deposited 
in two or more layers. The first must not be too thick, 
taking care that it is well rammed or pressed on the 
moist canvas surface without disturbing the white ce¬ 
ment. After the centring is struck any defects on 
the surface are made good. The surface may be then 
left white, or painted, or polished as required. 

Polished Soffits. —Soffits, landings and strings of con¬ 
crete stairs that are finished in white cement may be 
polished. The material may be tinted, or left in its 
natural white or creamy color. Polished cement work 
is always bright, and has a lustre like marble. Be¬ 
ing durable and easily cleaned, it is more sanitary and 


410 


CEMENTS AND CONCRETES 


cheaper than paint. The polishing is done the same 
way as described for 11 white work. ” 

Concrete Staircases and Fibrous Piaster .—Fibrous 
plaster is well adapted for concrete surfaces when an 
enriched finish is desirable. I have introduced this 
material for decorating the soffits of steps and land¬ 
ings ; also the strings of concrete stairs. By this method 
the soffits may also be enriched, and strings can be 
panelled, or enriched with medallions or foliage, as re¬ 
quired. The soffits may also be enriched with modelled 
work done in situ, with some of the white cements, or 
with plaster and tow. The strings may be decorated 
with hand-wrought gesso. In order to obtain a fixing 
or keying substance that will receive nails or screws 
to sustain the fibrous plaster, a rough plan of the de¬ 
sign, or rather the fixing points, is set out on the in¬ 
side of the centring before the concrete is laid. On 
these plans wood plugs, fillets or concrete fixing blocks 
are laid, and held in position with nails, plaster or ce¬ 
ment until the concrete is laid and set. Care must be 
exercised when fixing the plugs or fillets that the 
centring will leave freely without disturbing the plugs, 
etc. 

Dowel Holes .—Cutting dowel holes in concrete to 
receive iron or wood balusters is a slow and tedious 
process. They are best formed by means of wooden 
plugs, which are fixed before treads; the plugs are 
driven into the rough concrete before it is set, leaving 
them flush with the line of tread, so that when the 
topping is laid they will not be in the way. Plugs 
are best fixed by the aid of a wooden gauge. The 
gauge is made the same thickness as the topping, the 
length being equal to the distance between the nosing 


HOW TO USE THEM 


411 


mould and the riser board, and as wide as will admit 
of plug holes and the plugs to be driven through. The 
plugs are made a little larger than the baluster ends 
to allow for the lead. The gauge is laid on the rough 
concrete, using the returned nosing as a guide, and then 
driving the plugs flush with the top of the gauge. 
The gauge is then lifted up and laid on the next step, 
and so on until the finish. This method is accurate 
and saves measuring and marking the position of each 
hole on every step. When balusters are fixed on the 
ends of the steps, the plugs are fixed on the inside of 
the outer string. The plugs are generally left in until 
the balusters are ready for fixing. A ready method 
for forming “lewis” holes or other undercut sink¬ 
ings in concrete is performed by casting wedge-shaped 
blocks of plaster of the required form and'size, and 
then laying them in the desired positions while the 
concrete is soft. When the. concrete is set, the plaster 
blocks can then be easily cut out, leaving the under¬ 
cut sinking as desired. 

Summary of Staircases Constructed “in Situ .”—It 
will be seen from the foregoing that the operations em¬ 
ployed in the construction of concrete staircases formed 
m situ are: (1) setting out the stairs and landing; (2) 
fixing the wood framing; (3) gauging the materials and 
filling in; (4) removing the framing; (5) cleaning up 
the treads, risers and strings; (6) striking the soffit 
centring and finishing the soffits; (7) protecting and 
wetting the work until set and hard. 

Cast Steps .—Staircases are also constructed with 
steps cast separately, and then built in, in the same way 
as stone. Illustration No. 24 shows various sections 
of steps. Fig. 1 is a spandrel step, which may be used 


412 


CEMENTS AND CONCRETES 


for model dwellings, factories, etc. The tread is grooved 
to afford a good footing and prevent dipping. The 
dotted line indicates a square seating or tail-end of the 
step, which is embedded in the wall. Fig. 2 is a square 
^ step. Fig. 3 is a step with a moulded and returned 


Fig. i. Fig. 2. Fig. 3. Fig. 4- 



Sections of Steps. 
NO. 24. 


nosing. Fig. 4 is a similar step, but having a moulded 
soffit. For cast work these steps must have a square 
seating or tail-end, as indicated by the dotted lines on 
Fig. 1, so as to bond into the wall. 



Treads and Risers .—Stairs between walls are some¬ 
times formed with treads and risers. The treads and 
risers are cast and built in as the construction of the 
work proceeds. Sometimes they are let into chases and 
pinned after the walls are built. Illustration No. 25 
shows a section of treads and risers. 


























HOW TO USE THEM 


413 


Closed Outer Strings .—Staircases are sometimes fin¬ 
ished with a close outer string, which prevents dirt or 
wet falling into the well. Illustration No. 26 shows 
the section, Fig. 1, and the elevation, Fig. 2, of a 
moulding outer string. The dotted line at A indicates 
a dowel hole for the balusters. Outer strings, whether 
plain or moulded, are much stronger when formed in 



Fig. i. 


Fig. 2. 


NO. 26. 


situ. This is best effected by fixing a reverse mould 
at each side, then filling in the space from the top. The 
top is finished by hand and the aid of a template. The 
dowel holes are formed as already described. 

Concrete Floors .—It has been mentioned that the 
Romans, in the time of Julius Caesar, were in the habit 
of constructing their floors and roofs, as well as their 
walls, of concrete. According to an article in Archaeolo- 
gia, the cementitious agent was pozzolana. The lime 








414 


CEMENTS AND CONCRETES 


was obtained by burning ‘ ‘ traverstine. ’ ’ The aggregate 
usually consisted of broken tufa for walls, of broken 
lava for foundations where great strength was re¬ 
quired, and of broken pumice where lightness was es¬ 
sential. The floors were generally constructed of large 
slabs of concrete, supported on sleeper brick walls. 
The upper surface was finished with a layer of finer 
concrete and mosaic. The roofs were made flat, rest¬ 
ing on brick pillars. The first known English patent 
fireproof construction was obtained by one Dekins Bull, 
in 1633but as at that period patentees were not com¬ 
pelled to disclose what their patents covered, no de¬ 
scription of the materials and methods can be given. 
Up to the middle of the eighteenth century fireproof 
their great weight and cost, were seldom used. But 
towards the close of that century cast-iron girders and 
segmental brick arches were gradually coming into use 
where strength was essential. Up to a century ago 
plaster was largely employed as a floor material. In 
floors usually consisted of brick arches, but owing to 
1778 Earl Stanhope invented pugging for rendering 
wooden floors fireproof. By this process fillets were 
paled to the joists at about one-third of the- height. 
Laths were laid on the fillets and plastered above and 
below with a coat of lime and chopped hay. The under 
sides of the joists were then lathed and plastered in the 
usual way to form the ceiling. About the early part of 
the last century wrought iron joists were substituted 
for cast iron girders. Fox & Barret’s floor, designed 
about 1830, was the first in which an attempt was made 
to protect the exposed faces of the iron joists with a 
fire-resisting material. Hornblower’s floor is one of the 
earliest for resisting the effects of fire. Iron, bricks 


HOW TO USE THEM 


415 


and plaster are chiefly used in the French and Ameri¬ 
can systems. For the sake of simplicity and reference, 
concrete floors may be divided into three kinds: (1) 
“Joist"floors,” in which the concrete is laid slid be¬ 
tween the joists; (2) “Tabular floors/’ formed with 
fireclay tubes or hollow lintels placed between the 
joists and covered with concrete; (3) “Slab floors,” 
formed in one piece or slab. Portland cement concrete 
laid in situ on and between iron joists is extensively 
used for fire-resisting structures. Cast concrete is used 
for some parts of tabular floors. Cast concrete blocks 
are used for the ceiling surface, and as a support for 
the rough concrete floor surface. The blocks are hol¬ 
low, and have male and female dovetails on the sides. 
The ceiling surface of the floors and the outer surfaces 
of the partitions are finished with a thin setting coat of 
gauged putty or Parian. The chief objects of fire¬ 
proof floors are to render each floor capable of resist¬ 
ing the effects of fire, so that fire cannot be communi¬ 
cated from one floor to another, and by making the 
roof fireproof, to prevent the fire from spreading from 
one compartment to another; to gain additional 
strength, so as to avoid as far as possible lateral thrust 
on the walls, and to secure the building from attacks 
and effects of both dry rot and damp. There have been 
about a hundred -patents for fireproof floors during the 
past generation, of which about five or six survive. 

Plaster Floors .—Plaster concrete, that is, plaster and 
broken bricks, or similar aggregates, also neat plaster, 
were at one time used largely for the formation of 
floors. The use of plaster floors was common in some 
districts, and up to a century ago. the rough plaster, 
known as “floor plaster,” was in general use where 


416 


CEMENTS AND CONCRETES 


gypsum was found in abundance. Plaster floors were 
rarely used on the ground level, because they could not 
resist moisture, which caused them to become soft and 
retain the damp. They were principally used for up¬ 
per floors. The gauged plaster was laid upon reeds. 
These reeds were spread upon the tops of joists, and 
over them was laid straw to keep the soft plaster from 
percolating through the reeds. The floors were about 
3 inches thick, floated fair, and finished the following 
day. "Wood strips were placed around the walls, and 
drawn out when the plaster began to set, to allow for 
She expansion of the plaster. The materials being so 
light, the timbers were less in size and number than 
those now in use. The joists were in some instances 
3 y 2 inches by 2% inches, fixed wide apart, and sup* 
ported by small beams about 4% inches by 3% inches. 
The undersides between the joists were made fair by 
plastering the reeds, but in the better class of work the 
joists were covered with reeds, and held in position with 
oak laths, and plastered. Bullock’s blood was used to 
harden the floors after they were dry. In some in¬ 
stances they were coated with linseed oil to increase 
their hardness. Their use is now practically super¬ 
seded by Portland cement concrete. 

Joist Concrete Floors .—For this form of floor the 
concrete is laid between, over and under the iron joists 
Beyond the supervision of the fixing of the centring 
and the gauging of the materials, little skilled labor is 
required. The rough concrete is laid between and 
partly under the iron joists, which are fixed from 3 feet 
to 5 feet apart, according to the span and strength of 
the joists. The centring is supported, or rather hung, 
by the aid of timber laid across the joists and secured 


HOW TO USE THEM 


417 


by bolts. The materials are generally Portland ce¬ 
ment and gravel, coke-breeze, clinkers and broken 
bricks, gauged in the proportion of 1 part of matrix 
to 5 of aggregate. Sand equal to one-third of the 
bulk should be added. Coke-breeze is weak, light and 
elastic, but combustible and porous. A mixture of 
gravel and breeze in equal proportions is better than 
either alone. The proportion of cement varies accord¬ 
ing to the span and class of aggregate. All other 
things being equal, the strength of concrete is influ¬ 
enced by the strength of the aggregate, so that it 
would take a greater proportion of cement to make 
coke-breeze concrete equal in strength to a concrete 
made with hard aggregate, such as granite, slag or 
brick. The upper surface of this class of floor may 
be finished, with wood, tiles or fine concrete, as re¬ 
quired. Joist concrete floors have been largely used. 
This is principally owing to their supposed cheap¬ 
ness, but it is more than probable that, in the event 
of fire, they would be dear in the end, because the 
lower part of the flanges are barely protected from the 
effects of fire, as the concrete, being thin at these parts, 
and also on a comparatively smooth surface, would 
soon crack or scale off, and leave the flanges of the 
joists exposed to the ravages of fire. They are also 
more or less conductors of sound. Caminus concrete 
cement is an excellent material for the construction 
of fireproof ceilings and partitions. 

Caminus Concrete Cement .—This material is specially 
designed to produce a hard and practically indestructi¬ 
ble concrete for the construction of fireproof floors and 
walls. It is manufactured from a waste product, and 
all inflammable material, such as coke-breeze, being en- 


418 


CEMENTS AND CONCRETES 


tirely dispensed with, the concrete is thoroughly fire- 
resisting. It is lighter and much cheaper than Port¬ 
land cement concrete, and is perfectly free from ex¬ 
pansion and contraction whilst setting. It can be man¬ 
ufactured to set in a few hours, so that the centres 
can be struck the day after the floor is laid. It can 
be supplied in a ready aggregated condition, so that the 
bags may be hoisted direct to the floor where the con¬ 
crete is being laid, and gauged on the floor, thus sav¬ 
ing a great amount of waste, and also labor in handling, 
mixing and laying. 

Concrete Floors and Coffered Ceilings .—A method 
was patented by E. Ransom for decreasing quantity of 
material and yet obtaining equal strength in floors. The 
floor is divided by a series of beams at right angles 
to each other, so as to form a series of coffers in the 
ceiling. For instance, for a floor 12 inches thick, the 
floor proper would be about 4 inches thick, and beams 
about 3 inches thick and 8 inches deep—a rod of twist¬ 
ed iron being placed in the centre of the thickness, and 
near the lower surface of the beams. The beams are 
generally about 2 feet 6 inches from centre to centre. 
The method of construction is as follows: First, form 
a platform or centring; on this a series of core boxes 
2 feet 3 inches is placed, 3 inches apart, so as to form 
a 3-inch beam. The core boxes must be tapered and 
their upper edges rounded, so that they will draw when 
the centring is struck. The size of the core boxes may 
be altered to suit the size and requirements of the 
floor. With regard to the iron bars, the inventor says: 
4 4 It is of vital importance for the strength of the struc¬ 
ture that the iron bars be placed no higher in the beam 
than calculated for; that the longitudinal centre of 


HOW TO USE THEM 


419 


these bars should be at the lowest point; and it is ad¬ 
visable that the bars curve upwards slightly and uni¬ 
formly each way from the centre to the ends, so that 
the ends are from 1 to 3 inches higher than the cen¬ 
tres. By preparing the concrete bed on a correspond¬ 
ing curve, the natural sag of the bar, as it is being 
handled to its place, gives all the requisite facility to 
accomplish this purpose. No crooked or irregular 
twisted iron must be used; otherwise, when the strain 
comes upon it, it will perforce straighten and lengthen 
out, and weaken the structure in so doing. After 
placing the iron, the rest of the concrete is tamped in 
place, and the whole made to form a monolithic block. 
It is of vital importance that no stop be made in the 
placing of concrete from the time the beam is begun 
until the thickness of the beam is in place and a 
1 through joint’ is made. The web and the thickness 
must be one solid piece of homogeneous concrete.” 

Combined Concrete Floors and Panelled Ceilings .—A 
combined floor and panelled ceiling may also be formed 
in concrete. This is executed as follows: First, form 
a level platform or centring, and on this fix the re¬ 
verse piaster mould, run and mitred, according to the 
design of the ceiling. The intervening panels are then 
made up with framing, and the concrete filled in the 
usual way, and when set the centring and reverse 
mould are removed, and the ceiling cleared off. If de¬ 
sired, a finely finished and smooth white surface may 
be obtained by coating the surface of the moulds and 
panels with firmly gauged Parian, or other white ce¬ 
ment, until about % inch thick, and when this is firm 
(but not set), the rough concrete is deposited in layers 
and tamped to consolidate the concrete, and unite it 


420 


CEMENTS AND CONCRETES 


with the white cement. The surface may also be fin¬ 
ished with fibrous concrete. The method of doing this, 
also for carrying out the above white cement process, is 
described in “Fibrous Concrete.” 

Concrete and Wood .—Concrete floors finished with 
flooring boards require special care to prevent damp or 
dry rot. There are various methods in use for fixing 
and keeping the flooring boards from contact with the 
rough concrete, one way being to fix wood fillets to the 
joists by means of wedges or clamps. Another way 
is to embed wood fillets or fixing blocks in the rough 
concrete, leaving them projecting above the level of the 
iron joists, to give a bearing and fixing points to the 
flooring boards; or fine coke-breeze, concrete or plas¬ 
ter screeds, may be laid at intervals on the rough 
concrete, onto which the boards are nailed. Fixing 
blocks, concrete or plaster screeds, are preferable to 
wood fillets, as they do not shrink or rot, and will 
better resist fire. All these methods leave intervening 
spaces between the concrete and the boards, and unless 
thoroughly ventilated, they harbor vermin, dirt and 
stagnant air. Unless the wood is thoroughly seasoned, 
and the boards grooved and tongued, dust and ef¬ 
fluvia will find egress through the joints. A portion of 
dust and water when sweeping and washing the floors 
also finds egress through the joists; and as the concrete 
will not absorb the water, or allow the dust to escape, 
they accumulate and become unseen dangers. These 
sanitary evils may be obviated, or at least reduced to 
a minimum, by laying the boards direct on the con¬ 
crete. This not only forms a solid floor with no inter¬ 
spaces, but admits of thin boards being used with as 
much if not greater advantage than a thick board. 


HOW TO USE THEM 


421 


There is no uneven springing between the joists, which 
causes friction and opening of the joints, and the whole 
thickness is available for wear. There is also less total 
depth of floor, consequently less height of building and 
general cost. Another important advantage of a solid 
floor is that it wdll resist fire better than one with hol¬ 
low spaces. It is here that the sponginess and elasticity 
of coke-breeze concrete as a top layer is of special 
service, and where it may be utilized with advantage. 
Owing to its being able to receive and retain nails, the 
boards can be nailed at any desired place. Wood 
blocks for parquet floors can also be bedded or screwed 
on the concrete surface. Flooring boards will lie even 
and solid on this surface, and if a thin layer of felt or 
slag-wool be spread on the concrete before the boards 
are laid, a firm and noiseless floor is obtained. Slag- 
wool is an imperishable non-conductor of heat, cold 
and sound, and it will not harbor vermin. If the work 
is in humid climate, the coke-breeze surface when dry 
should be coated with a solution of tar and pitch, to 
prevent atmospheric moisture being absorbed by the 
porous coke-breeze. 

Concrete Drying .—To prevent dry rot It is of the ut¬ 
most importance that the concrete should be thoroughly 
free from moisture before the flooring boards are laid 
and fixed. The drying of concrete is a question of 
time, which depends upon the amount of water used 
for gauging, the thickness and the temperature. It 
may take from three days to three weeks or even three 
months. The drying can be accelerated by directing 
currents of hot air on the lower surface, or by laying 
some absorbent material, such as dry sawdust or brick 
dust, on the upper surface. As soon as the surface 


422 


CEMENTS AND CONCRETES 


moisture is absorbed, or the dry material has no further 
absorbent power, it should be removed to allow the 
mass to be air dried. Another way is to lay the floor 
in two coats, and to allow one coat to dry before the 
other is laid. For instance, if the floor is to be 6 
inches thick, the first coat is laid with rough, but 
strong concrete, the aggregate being the best available; 
but taking gravel and coke-breeze to be the most 
plentiful, it will be best to assimilate and combine the 
good qualities of each to equalize their defects by mix¬ 
ing them in equal proportions. If brick is plentiful, 
and broken to properly graduated sizes, it will give 
better results than gravel or breeze. The mixed ag¬ 
gregate is gauged 5 parts to 1 of cement, and laid 4% 
inches thick, and gently but firmly beaten in situ, the 
surface being left rough to give a key for the second 
coat. The second coat is not laid until the first is 
dry, and consists of one part cement to 5 of sifted and 
damped coke-breeze, gauged stiff, and laid 1% inches 
thick, beaten in situ, ruled level, and any ridges being 
laid fair with a long hand-float. The moisture of the 
second coat, by reason of the density of the first coat, 
will only be absorbed to a small degree, while the 
greater portion will be taken up by the atmosphere, 
and enable the combined coats to dry sooner than if 
laid in one. The first coat should be laid as soon 
as the roof is on, so as to give all possible time for it 
to dry, and the second coat to be laid and dried before 
the flooring is laid. When coke-breeze is not avail¬ 
able for the second coat, use soft brick, broken to pass 
through a 3-16-inch sieve. The method of laying floors 
in two coats is only given as an alternative plan, and 
as an example of a process used in some parts. Greater 


HOW TO USE THEM 


423 


strength, as a whole, and more perfect cohesion be¬ 
tween the two coats, is obtained by laying the second 
coat as soon as the first is laid, or at least while it is 
green. 

Concrete Slab Floors .—The term, slab floor, is applied 
to a concrete floor formed in situ, and in one piece or 
slab. It must not be confounded with slab pavements, 
which are constructed with a number of small cast 
slabs. Slab floors are usually made without exterior 
iron supports, but in a few instances iron T pieces or 
bars have been used as internal supports. Bearing in 
mind the lasting properties of the old Roman slab 
floors, and the enormous strength of the modern exam¬ 
ples at home, which are unsupported by iron, and are 
practically indestructible, it seems strange that they are 
not in more general use, and that for some inexplica¬ 
ble reason preference is given to shrinking, rotting 
and combustible floors, composed of poor iron and tim¬ 
ber instead of the best work and material, which, if a lit¬ 
tle dearer at first, is infinitely superior and vastly 
cheaper in the long run. The great sanitary advan¬ 
tages and fire and damp resisting powers of concrete 
slab floors are the highest known. The construction of 
slab floors is simple, and similar in many respects to 
that already described for stair landings and ordinary 
concrete and joist floors. There are several methods 
of supporting the floors, the first and most common 
being to leave a sand course or to cut a horizontal chase 
in the walls to receive the ends of the floors. The 
second is to lay the floors when the walls are floor 
high, and build the higher walls on it when set. This 
method, while making sound work, is not always prac¬ 
ticable or convenient, owing to the delay in building 


424 


CEMENTS AND CONCRETES 


while waiting for the floors to set. The third method 
is to build corbelled ledges in the walls, so as to carry 
the floors. The centring for slab floors should fle per¬ 
fectly rigid, water-tight and slightly cambered towards 
the ceiling centre. This camber gives more strength 
to the floor, and lessens liability to crack when remov¬ 
ing the centring. If joists are not used, the centring 
is supported on wall boards and centre struts. An¬ 
other way which gives great additional strength is to 
form the centring level, but having all the edges at the 
wall rounded off, so as to form the floor like an in¬ 
verted sink or tray. The horizontal chases in this case 
should be made wider than the thickness of the floor to 
allow for a thickness of rim. The extra width of chase, 
which may be one or two bricks thick, according to the 
width of span, is made below the centring or line of 
ceiling, the angles being coved by rounding the edges 
of centring. The coved rim gives greater strength 
with a less thickness of floor. The cove may be left 
plain or used for a cove for a plaster cornice, or rough¬ 
ened and used as a bracket for the same purpose. The 
expansion of concrete floors having large areas, or 
where hot cement has been used, has been known to 
disturb the walls, causing cracks and displacement of 
brick and stone work. This may be prevented by 
isolating the floor ends from the walls. This is done 
by forming expansion partitions or linings in the chases, 
the linings being composed of slag, felt or wood shav¬ 
ings, straw, reeds or other compressible material. The 
chase should be sufficiently deep to allow for a com¬ 
pressible lining about 1% inches thick, and a fair bed 
for the slab floor. Care must be taken to leave a few 
half bricks solid at intervals, say from 3 to 4 feet 


HOW TO USE THEM 


425 


apart, to support the upper walls until the floor is set. 
Compressible linings may be used for floors supported 
on corbelled ledges; and when the expansion, and in 
many cases subsequent contraction, has finally finished, 
the linings can be taken out, and the vacant space 
filled up with fine concrete, or utilized as a ground key 
for cement skirtings. If girder or iron posts are iso¬ 
lated from the walls by means of compressible linings, 
the effects of expansion and sound are limited. In 
some instances a judicious use of iron may be made. 
For instance, large areas may be divided with three or 
four rolled iron joists, so as to form shorter spans or 
smaller bays. Joists tend to bind the walls together, 
and to serve as scaffold bearings for building the upper 
parts of walls. They may also be used for hanging 
the centring on instead of strutting, or as aids to \,he 
strutting. Joists may also be used as integral sup¬ 
ports at unsupported ends of concrete floors. They 
should be so fixed that the lower flanges are not less 
than 1 inch above the lower surface of the concrete. 
The whole strength of iron is brought more fully into 
use by fixing it near the lower surface. If fixed near 
the centre, or at the axis of neutral stress, a correspond¬ 
ing part of the strength is comparatively of little 
value. 

Construction of Slab Floors .—Portland cement as a 
matrix is indispensable. The unequal nature of gravel 
and coke-breeze renders them unfit and unsafe aggre¬ 
gates for this class of work. Broken brick being cheap, 
and obtainable in most districts, affords a ready aggre¬ 
gate, and may be used with safety and success. In 
ordinary cases of concrete construction, the whole 
thickness is usually made with one rate of gauge; but 


426 


CEMENTS AND CONCRETES 


for slab floors covering large areas, and unsupported 
by iron or other supports, exceptional strength is re¬ 
quired. Stronger results are obtained by making up 
the whole thickness with different rates of gauge. Tak¬ 
ing the usual gauge for floors as from 4 to 5 parts of 
aggregate to one of cement, and used for the whole 
thickness, it gives an unequal strength, a part of which 
is comparatively of little use, especially at the neutral 
axis; but if the cement is divided so as to form an 
ordinary coat in the centre, and stronger coats at the 
upper and lower surfaces at the points of greatest 
strain, the upper being compressive and the lower ten¬ 
sive, a better and more accurate arrangement of 
strength and allowance for disposition of strains is ob¬ 
tained. The additional strength at the proper places 
is obtained not only by the use of additional cement, 
but by the method of construction, which enables the 
same quantity of cement as gauged for the usual rate 
for forming the whole thickness in one coat to 
be used more profitably. Take the section of 
an iron joist as an example; this gives divided 
yet united strength, which sounds paradoxical, 
but is true. The flanges sustain the greatest 
strains, and the web comparatively little. With con¬ 
crete, the strong coats at the upper and lower surfaces 
represent the flanges, and the ordinary coat the web. 
As already stated, the increased and profitable dis¬ 
tribution of strength is obtained by the method of con¬ 
struction. For instance, take a slab floor 20 feet by 
14 feet and 12 inches thick, without iron joists or other 
supports, and intended to carry a safe load of 2% cwt. 
per superficial foot, in addition to its own weight of say 
1 cwt. per square foot. This floor is laid in three coats, 


HOW TO USE THEM 


427 


the first composed of 1 part cement and 2 of fine broken 
bricks gauged stiff, and laid 2 inches thick; the second 
composed of 1 part cement and 6 of coarse broken 
bricks gauged stiff and laid and rammed 8 inches thick; 
and the third composed of 1 part cement and 2 of fine 
broken bricks gauged stiff and laid 2 inches thick. 
If the upper surface is intended for hard frictional wear 
a slight difference is made in the gauge and materials. 
The first coat is composed of 2 parts of cement and 5 of 
fine broken bricks gauged stiff and laid 2 inches thick; 
the second of 1 part cement and 6 of coarse broken 
bricks gauged stiff and laid and rammed till 8 inches 
thick; and the third coat composed of 1 part cement and 
2 of fine crushed slag or granite. It will be seen that 
this constructive method gives the desired positions of 
strength, and the total quantity of cement in the united 
gauges is 1 part to 4, and up to 5 parts of aggregate. 
The fine broken bricks should be passed through a %- 
inch sieve, and the coarse through a 2-inch screen, 
taking care that the latter contains a greater quantity 
of the smaller pieces than of the larger. It must be 
clearly understood that the second coat must be laid 
before the first is set; also that the third is laid before 
the second is set, so as to ensure perfect cohesion be¬ 
tween each coat, and the absolute homogeneity of the 
whole mass. 

Hollow Floors .—Greater lightness in concrete floors is 
obtained by the use of concrete tubes. If the tubes are 
placed apart and in the centre of the floor thickness, 
a hollow homogeneous concrete slab is formed. The 
vertical divisions between the tubes connect the upper 
and lower coats, as with a web of a joist connecting the 
upper and lower flanges. The method of construction 


428 


CEMENTS AND CONCRETES 


is simple and expeditious. For example, for a slab 
floor 10 inches thick, first lay a coat 2 inches thick of 
the stronger and finer concrete, as described for the 
12-inch slab floor, and when this is firm lay 5 or 6- 
inch tubes from wall to wall. Bed the sides with rough 
concrete, and lay another row of tubes parallel with the 
first row and about 2 inches apart, and so on until the 
floor area is covered; then make up interspaces with 
rough concrete till level with the upper surfaces of the 
tubes, and then cover this with a coat of fine concrete 2 
inches thick. Concrete tubes or common earthenware 
drain pipes may be used. Half-circle pipes, laid on 
their side edges, may be used to save concrete and 
weight in joist floors, etc. 

Concrete Roofs .—Concrete roofs require special care 
to render them watertight. Subsidence in the brick 
work of new buildings is often the cause of cracks on 
concrete roofs. The roof should have a good camber, 
to give greater strength and allow for the fall of wa¬ 
ter to the outer edges. The rough coat should be laid 
and well consolidated by ramming or beating, and then 
left for seven days (the longer the better) before the 
topping is added. The upper coat should be strongly 
gauged with fine aggregate, as in “Eureka.” If possi¬ 
ble, the topping should be laid in one piece. If the 
area is too large to be laid and finished in one piece, 
the joints of the bays should overlap. This is done 
by rebating the screed rules, so as to allow one-half of 
topping thickness to go under a part of the rule and 
form an underlap or ledge about % inch wide, and 
when the adjoining bay is laid an overlapped but level 
joint is the result. Roofs exposed to the sun’s heat 
should be kept damp for several days after being laid, 


HOW TO USE THEM 


429 


as joints are affected by the heat as well as by deflec¬ 
tion of centring or subsidence of walls. Compressible 
linings or wood strips should be used round the walls 
to counteract any expansion. All concrete roofs should 
have a cement skirting 6 inches high and 1 inch thick 
well keyed into the walls. If linings are not used when 
the topping is laid, the topping should be turned up on 
the walls, so as to form a rim, to prevent water get¬ 
ting between the roof and the walls. Greater heat and 
damp-resisting powers are obtained by laying the up¬ 
per surface with i^-inch thick coat of special concrete, 
composed of 1 part of Portland cement, y 2 part of 
slaked lime and 1 part of firebrick dust. This should 
be consolidated with a hand-float, and finished fine and 
close with a trowel. 

Notes on Concrete .—When calculating the strength of 
floors, stairs, etc., the following facts should be borne 
in mind: Portland cement, when new, is too hot; sets 
more rapidly and expands more than old cement. The 
finest ground cement is the best and strongest. The 
time in setting, and in which the maximum strength is 
attained, varies according to the age of the cement, the 
quantity of water used, and the mode of gauging and 
the mean atmospheric temperature. The maximum 
strength of a briquette of mature cement is maintained, 
while one of new cement “goes back.” A briquette of 
matured cement will stand a tension strain of 550 
pounds per square inch, and a crushing weight of 6,000 
pounds per square inch. A briquette of neat cement is 
more brittle than one of concrete. Briquettes mature 
more rapidly than thick slab floors. The adhesive 
strength of Portland cement is about 85 pounds per 
square inch. The adhesive strength increases more 


430 


CEMENTS AND CONCRETES 


rapidly than the cohesive. A mass with a surface 
large in proportion to its volume sets more rapidly than 
a mass with a small area in proportion to its volume. 
Masses subject to pressure set more rapidly and attain 
greater hardness than masses not so pressed. The 
average* compressive strength of concrete is about eight 
times its tension strength. The proportion of com- 
pressional and tensional strength varies according to 
the quality and quantity of the aggregate. The strength 
of concrete depends greatly on the proportion of the 
matrix and aggregate; also on the strength of the lat¬ 
ter. As regards bricks, it must be remembered that 
there is a wide difference between the tensile strength 
of hard, well-burnt bricks and soft stocks. No bricks 
are so strong as cement, the best kinds being about 
one-fourth the strength of neat cement. Taking the 
gauge as one part of cement to 4 of broken brick, the 
strength of the concrete will be about two-fifths of neat 
cement, but for safe and practical calculations it will 
be best to take the strength as one-fourth of neat ce¬ 
ment. Square slabs are stronger than rectangular 
slabs. Slab floors being homogeneous throughout, the 
whole weight is a dead weight, and consequently there 
is no thrust on the walls. With regard to the live load 
or weight which floors should be constructed to carry, 
some difference of opinion exists. Hurst says that for 
dwellings 1*4 cwt„ public buildings % cwt. and ware¬ 
houses and factories 2 y 2 cwt. are safe calculations. 
Others assert that for domestic buildings 1 cwt. per foot 
would be ample for all contingencies. An American 
authority states 40 lbs. is sufficient for ordinary pur¬ 
poses. The following table shows the results of tests 


HOW TO USE THEM 


431 


of slab floors made without iron. The slabs were sup¬ 
ported all round, and uniformly loaded with bricks. 


Test of Slab Floors. 


No. 

Length 

between 

Sup¬ 

ports, 

feet. 

Breadth 

between 

Sup¬ 

ports, 

feet. 

Thick¬ 

ness, 

feet. 

Age in 
Days. 

Breaking 
Weight, in 
cwt. per 
sq. ft. 

Weight of 
Slab,in 
cwt. per 
sq. ft. 

Total 
Breaking 
Weight, in 
cwt. per 
sq. ft. 

1 

14.5 

6.75 

.5 

7 

3. 

.54 

3.54 

2 

<( 

<( 

a 

14 

2.76 

a 

3.30 

3 

u 

a 

a 

21 

8.88 

a 

9.42 

4 

a 

13.5 

a 

7 

1.07 

it 

1.61 

5 

a 

6.75 

a 

14 

2.51 

a 

3.05 

6 

a 

a 

a 

21 

2.84 

a 

3.38 


Cast Concrete .—Innumerable patents have been ob¬ 
tained for a combination of materials, also moulds for 
the construction of artificial stone. Among the many 
that may be mentioned is Mr. Ranger’s system. He 
obtained a patent in 1832 for artificial stone formed 
with a lime concrete. The aggregate consisted of 
shingle, broken flints, mason’s chippings, &c. The in¬ 
ventor stated that the best results were obtained by 
using 30 lbs. of an aggregate of a siliceous or other 
hard nature, 3 lbs. powdered lime, and 18 ozs. boiling 
water. No more of the materials were gauged at the 
time than were sufficient to fill one mould, as the boil¬ 
ing water caused the concrete to set very rapidly. This 
material, after fifty years’ exposure is still sound and 
shows no sign of decay. No artificial stone equals, far 
less excels, the strength and durability, sharpness, and 
evenness of Portland cement concrete. This form of 
artificial stone is now extensively used as a substitute 



















432 


CEMENTS AND CONCRETES 


for natural stone, for window heads, string courses, 
sills, columns, copings, keystones, and many other archi¬ 
tectural, constructive, and decorative features. Fig¬ 
ures, animals, bas-reliefs, capitals, panels, can he made 
in fine concrete with all the relief, undercut, and fine 
detail which distinguishes high-class from inferior 
work. Cast work has the advantage over in situ work 
that any defect can he detected previous to fixing. The 
methods of moulding and casting various works are 
given in the following pages. 

Concrete Dressings .—Architectural works, especially 
large or plain parts, are generally cast in wood moulds. 
If there are ornamental parts in the blocks, a combina¬ 
tion of wood and plaster, and sometimes gelatine, is 
used for the moulds; wood for the main or plain parts, 
plaster for circular or moulded parts, and gelatine for 
undercut parts. The plaster or gelatine, as the case 
may be, is screwed on or let into rebated parts of the 
wood. Ornamental parts are sometimes cast separately, 
and then fixed on the main cast. They may also be 
cast separately and laid into the main mould (face 
inwards), and the whole is cast together in a somewhat 
similar way to that described for “ bedded enrich¬ 
ments” in fibrous plaster cornices. 

Considerable skill and ingenuity has been displayed 
in the construction of wood moulds for casting concrete 
blocks for architectural purposes. Many methods have 
been employed for fixing the sides and ends together, 
and also to the bottom of the mould, leaving one or 
more parts unfixed to facilitate the release of the cast. 
The primitive method is to fix the various parts of the 
mould with screws. This is a slow and unreliable 
process, as the continual screwing and unscrewing for 


HOW TO USE THEM 


433 


each cast soon wears the screw-holes, and the sides be¬ 
come loose and out of square, causing the casts to get 
out of their true form. Hinges, also hooks and eyes, 
have been used for the same purpose, but they are 
liable to the same defects as the screws when subject 
to long use. 



—Wedge Mould for Casting Blocks, Moulded 
Lintels, &c. 

NO. 27. 


Thumbscrews to fit into iron sockets are also used, 
but they are too expensive for ordinary work, and are 
unsuitable for small moulds. One of the most simple 
and reliable methods is the “wedge mould,” invented 
by an architect. It is easily made, and expeditious in 
working. Even after long and constant use, the casts 
are always accurate in form and size. The wedges and 
the rebated ends allow the various parts to be correct¬ 
ly fixed and held in position. Illustration No. 27 shows 
the method of construction. The various parts are 






434 


CEMENTS AND CONCRETES 


named, and the sketch is self-explanatory. When the 
moulds are extra deep, it is necessary to make two or 
more sets of tenons and wedges at each angle. When 
there are a large number of casts required the mould 
ends are strengthened by binding the projecting ends 
with hoop iron. This method has been adopted for 
casting a lot of blocks. Illustration No. 28 shows two 
useful kinds of moulds. Fig. 1 is a simple form of 
mould adapted for plain blocks, caps, lintels, &c. A, A, 
are the sides, which are grooved into the ends B, B, and 


Fig. i. Fig. 2. 



NO. 28. 


held together by the bolts and nuts, C, C, two on each 
side. The bolts may be about % inch diameter, with 
a good-sized square-head at one end, and a washer and 
nut at the other. This, having no bottom, is termed a 
bolted frame mould. It should be laid on a bench or 
moulding board before the cast is filled in. Fig. 2 is 
a section of a combined wood and plaster mould on the 
wedge principle, adapted for casting a strong course 
moulding. A is a moulding board, 1 % inches thick, 
formed with two or more boards; a is one of two or 
more cross ledges, 1 inch thick, on which A, the ground, 
is nailed. B is a width board, 1 inch thick, which is 












HOW TO USE THEM 


435 


nailed on to A. This gives a point of resistance to the 
plaster piece C and the side hoard G. D is a side board 
on which E is screwed. E forms the sloping part of 
the weathering. F is one of two or more vertical 
wedges which hold D E in position. The sockets for 
the wedges F are made between the cross ledges, so 
that the wedge will project below the ground A. This 
allows the wedges to be more easily driven out when 
the cast is set. G is the back or plain side board. H 
is a fillet, 1 y 2 inches square, screwed on to the ground 
A. I and J are two folding wedges, or, in other words, 
wedges driven in opposite directions. These hold G 
in position. Two or more of these folding wedges are 
required, according to the length of the mould. The 
same remarks apply to the vertical wedges F. The lat¬ 
ter form of wedge is only given as an alternative. The 
end pieces are held in position by dropping them into 
grooves in a similar way as shown in the previous fig¬ 
ure, with the exception that the grooves are cut in the 
sides instead of the ends. K is a gauge rule which is 
used for ruling the upper surface of the cast fair. This 
may also be done by working a straight-edge longi¬ 
tudinally. The dotted line at L, the concrete, indicates 
the wall line. The level part of the weathering up to 
this line, or if splayed from the outer member of this 
line, must be finished smooth to allow the water to run 
freely off. When the cast is set, the wedges are with¬ 
drawn, and the sides and ends released. The cast is 
then turned over on its back end or top side on a board, 
and then the plaster piece and the wood ground is taken 
off. If the cast is green, it should be turned over on 
old sacks or wet sawdust, so as to protect the arrises, 
and avoid fractures. 


436 


CEMENTS AND CONCRETES 


Illustration No. 29 shows a method commonly 
adopted for constructing moulds for sills and copings. 
Fig. 1 is the section of a mould for a window sill. A 
is the moulding board, made with two or more pieces, 
each l 1 /^ inches thick; a is one of two or more cross 
ledges, made with 1 inch stuff, on which A is nailed. B 
is the width board, made of % inch stuff, nailed on to 
A. C is a block, 1% inches thick, which is nailed on 
to B. These blocks are placed about a foot apart, or 
so that they will carry the lining D, 1 inch thick. A 


Fig: i. Fig. 2 . 



Fig. i.—Section of Mould for Casting Sills. 
Fig. 2.—Section of Mould for Casting Coping. 
NO. 29. 


groove or an iron tongue E is made in B, and a piece 
of thick hoop iron or iron bar is placed loosely in the 
groove before the cast is filled in. F is a fixed side, 
1!/4 inches thick. G is a fillet, 1% inches square, nailed 
on to F, and screwed on to moulding board A. H is a 
loose side, 1*4 inches thick, on which the fillet I is 
nailed. J is one of two or more clips, which turn on 
a screw, and are used to hold the loose side H in posi¬ 
tion. These clips are made and used in the same way 
as described for fibrous slabs. As compared with 
wedges, clips are always in position ready for use, are 
















HOW TO USE THEM 


437 


not liable to be mislaid, and when the fillets are fixed 
on to the side pieces, the clips keep the sides from 
rising as well as expanding. K is a throating or water 
groove, which is formed in the concrete L, with a rule 
having a rounded edge. Two blocks, dished at the 
inner ends, must be fixed one at each end of the mould, 
so as to form a stool or bed for the superstructure. The 
position and form of the groove is obtained from sink¬ 
ings cut in the end pieces of the mould. The end pieces 
are held in position by grooves cut in the side pieces 
in a similar way, as already described, with the excep¬ 
tion that the grooves are cut in the side pieces, instead 
of the end pieces. When setting out the mould, an 
extra length must be allowed for the side pieces for the 
grooves. A part of the upper surface of the cast (be¬ 
ing the part which projects beyond the line of wall) 
must be finished fair by hand at the same time as form¬ 
ing the water groove. This must be done while the cast 
is green. When the cast is released from the mould, 
the iron tongue will be found firmly embedded in the 
concrete. Fig. 2 is a section of a wood mould adapted 
for casting wall copings. A is the ground of a mould¬ 
ing board, which may be made of 1 Vi-inch stuff, and in 
2 or more, widths; a is one of two or more cross ledges, 
1 inch thick, on which A is fixed. B, B, are blocks 
about I 14 inches thick, placed about 1 foot apart. C, 
C, are linings, 1 inch thick, nailed to B, B. D is a 
fixed side, 1% inches thick. E is a fillet, 1% inches 
square, fixed to D, and then screwed on to A. F is a 
loose side, 1*4 inches thick, on which is nailed the fillet 
G, V /2 inches square. This strengthens the sides and 
affords the fixing point for the clip H. The water 
grooves I, I, and the hollowed part in the middle of the 


438 


CEMENTS AND CONCRETES 


concrete J (made to save materials in weight) are 
worked from the end pieces of the mould, which are let 
into the grooves, as described in the previous diagram. 
If the moulds are deep, wood or iron clamps may he 
fixed across the sides to keep them in position, as shown 
by K. The moulding boards in this and the previous 
figures, if strongly made, can be used for a variety of 
similar purposes. When introducing cast instead of 
run moulded work, I used iron and zinc plates to 
strengthen and make more durable plain surfaces on 
wood moulds; hut owing to the expense and trouble in 
fixing the plates to the woodwork, they were aban¬ 
doned, and by using a better class of wood, and in¬ 
durating the surface of the mould with hot paraffin 
wax, sharp and clean casts were more cheaply pro¬ 
duced. Cast-iron moulds may be used where there is 
a large number of casts required. They may also be 
advantageously used for stock designs, such as plain 
moulded balusters. Wood moulds are rendered more 
durable and impervious to wet by brushing them with 
hot paraffin wax, and then forcing it into the wood by 
ironing with a hot iron. The use of paraffin wax and 
oil has already been described. 

Mouldings Cast “In Situ .”—Casting cornices, cop¬ 
ings, &c., in situ is now frequently employed for con¬ 
crete. The advantages of this system over shop cast 
work, are, that the work is readily done, and the cart¬ 
age or moving from the workshops to the building, and 
the fixing, are dispensed with. 

Illustration No. 30 shows the method of constructing 
and fixing various kinds of casting moulds for in situ 
work. 

Fig. 1 shows the section of a cornice, casting mould, 


HOW TO USE THEM 





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440 


CEMENTS AND CONCRETES 


and supporting bracket. Wood moulds are generally 
used for small or plain mouldings, but where the profile 
is undercut or of an intricate nature, a plaster mould 
is preferable, as it is easier and cheaper to construct a 
plaster mould than cut the irons which are necessary 
for a wood mould for a special design. Fibrous plaster 
moulds may be used for this class of work, but to illus¬ 
trate another method a combined wood and plaster 
mould is given. M is a moulding board to strengthen 
the plaster profile, and on which it is run. The board 
may be made in two or more pieces, each about 1 inch 
thick, and in width according to the depth of the mould¬ 
ing, and in length as required, the whole being held 
together by cleats H, which are nailed about 3 or 4 feet 
apart. Broad-headed nails are then driven in at ran¬ 
dom, leaving the heads projecting, to give a key for 
the plaster profile P. The profile is then run with a 
reverse running mould. It will be seen that this profile 
is undercut, therefore a loose piece L is required to 
enable the mould to draw off the moulding. The re¬ 
verse mould and loose piece are constructed in the same 
way as described under the heading of “ Reverse Mould¬ 
ings.” It may be here remarked that it is sometimes 
useful to have an “eye” inserted in the loose piece to 
give a better hold for the fingers when taking the loose 
piece off the moulding. The eyes are made by twisting 
a piece of strong wire round the handle of a tool bruch, 
leaving one end in the form of a ring, and the other 
bent outwards so as to form a key. The eyes are fixed 
about 3 or 4 feet apart, the fixing being done by cut¬ 
ting a hole in the loose piece and bedding the shank of 
the eye with plaster, and then cutting a slot in the 
main part of the mould to receive the ring of the eye 


HOW TO USE THEM 


441 


as shown at E. The mould is held in position by the 
bracket B, fixed 4 or 5 feet apart. The mould is further 
secured by the stay S, the other or inner end of the 
stay is fixed on to the main wall. It will be understood 
that a plaster mould for this purpose should be dry and 
hard, and then well seasoned with linseed oil, or with 
a hot solution of paraffin wax. After the mould is fixed 
in position it is oiled, and then the concrete C is filled 
in, taking care that the surface of the mould is first 
covered with a thin coat of neat cement. The mould 
may be oiled with paraffin oil; but if the mould is in¬ 
clined to “stick/’ oil it with “chalk oil,” i. e., paraffin 
oil and French chalk, about the consistency of cream. 

When the concrete is set, the brackets are removed, 
and the mould taken off. The mould in this case would 
draw in the line of the arrow A. The loose piece is 
then taken off. It is here that the use of the eyes will 
be found. Before removing the brackets it is advisable 
to prop the mould, in case it may drop off and break 
the fragile portions of the mould or parts of the cornice. 
A heavy mould hanging in this position, especially if 
the profile is flat, or in good working order, is apt to 
drop, hence the necessity of props. If the mould clings, 
or, as more generally called, “sticks fast,” gentle tap¬ 
ping with a heavy hammer will ease or spring it, and 
allow it to be taken off. A heavy hammer is more ef¬ 
fective in making the mould spring than a light ham¬ 
mer, as the force required for a light hammer is apt to 
injure the mould. This is why a heavy hammer with a 
flat head is best for plaster piece moulding. 

Fig. 2 is the section of a string moulding with the 
casting mould and bracket. A chase is formed in the 
brickwork to allow it to bond, and the joints and the 


442 


CEMENTS AND CONCRETES 


surface of the brickwork are cut out and hacked to give 
a further key to the moulding. M is the mould (in this 
case made of wood). The profile is drawn without any 
undercut parts, so as to allow the mould to draw off in 
one piece. B is the bracket, and C is the concrete. The 
same directions for casting Fig. 1 apply to this and 
the other moulding here shown. A drip member, as 
shown at the top member of both cornices, is generally 
used for exterior mouldings, to prevent the water run¬ 
ning over the wall surface. 

Fig. 3 is the section of a wall coping and the casting 
mould. M is the mould, a similar one being used for 
the other side. A mould for this purpose is best formed 
with flooring boards about 1 inch thick, and fixing them 
together as shown. The drip D is readily formed by 
sawing an inch bead through the centre, and nailing it 
on the bottom. Two forms of brackets, B and B, are 
here given. One is cut out of the solid, and the other 
made of two pieces of wood nailed together. 

Fig. 4 is the section of a casting mould for a saddle¬ 
back coping. R is a quarter-round piece of wood fixed 
in the angle of the mould to form a cavetto, which is 
sometimes used in copings. D is an angular-shaped 
drip, sometimes used in place of a circular one. T is 
part of a template used for forming the saddle-back of 
the coping. 

Fig. 5 is the section of a mould for a coping with 
splayed or chamfered angles. S is a triangular strip 
of wood fixed in the angle and the top of the mould to 
form the splays, and D is a circular drip. 

Concrete mouldings that are deeply undercut or in¬ 
tricate in profile may be cast in situ by the use of the 
“Waste Mould Process.’’ 


HOW TO USE THEM 


443 


Modelling in Fine Concrete .—Figures of the human 
and animal form, also emblems, trade signs, and build¬ 
ings, are now being made in fine concrete. The work 
may be executed in situ, or in the moulding shop, and 
then fixed in position. For important works a plaster 
model is first made, and placed in position, so as to 
judge of the effect before committing it to the perma¬ 
nent material. For this purpose the model is first 
modelled in clay, and then it is waste-moulded, and a 
plaster cast obtained. After the model is approved it 
is moulded, and then cast in the fine concrete. The 
material is composed of Portland cement, and a light, 
but strong, aggregate; and the cast is made in a similar 
way to that described for casting vases. The material 
may be colored as required to suit the subject. The 
general method of executing figures “on the round” 
in fine concrete or Portland cement is to model the 
figure direct in the cement on an iron frame, and then 
to fix it in its permanent position. This is effected by 
first making a full-sized sketch of the proposed figure, 
then setting out on this the form of the necessary iron¬ 
work to serve as frame or skeleton to form an internal 
support. This iron frame also forms a core to enable 
the figure to be made hollow, and serves as a permanent 
support for thin parts and extremities of the figure. 
The quantity, size, and form of the iron frame is regu- - 
lated by the size, form, and position of the figure. For 
instance, if the model of a full-size lion is required, first 
make a rectangular frame to suit the feet of the lion 
and the base on which the figure stands. The base 
frame is made of iron bars, l 1 /^ inches wide by % inch 
thick, fixed on edge. Then set out four leg-irons, and 
connect them on the base frame, and then set out one 


444 


CEMENTS AND CONCRETES 


or two body-irons, and connect them with the leg-irons. 
After this set out a looped piece to fit the contour of 
the neck and head, and fix it to the body-iron. Now 
set out the tail-iron. This is best formed with an iron 
pipe, and it should be made to screw on to the body- 
iron. This allows the tail to be unscrewed when the 
model is finished, and screwed on after the model is 
fixed in position, thus enabling the model to be more 
freely handled, and with less risk of breakage when 
moving and fixing in its permanent position. 

Having made the frame, place it on a stout modelling 
board, keeping the base frame from 1 to 3 inches above 
the board, according to the depth of the base; the frame 
being temporarily supported with four pieces of brick 
or stone. This is done to allow the base frame to be 
enveloped with concrete. This done, fix wood rules, cut 
to the depth of the base, on the board, so as to form 
a fence on all sides of the base. Then fill in the base 
with concrete; and when this is set, proceed with the 
coring out, so as to obtain a hollow model. 

In order to decrease the weight of concrete figures 
“on the round/’ and to enable them to be more easily 
handled and hoisted when fixing them in their perma¬ 
nent positions, they should be made hollow. This is 
effected by making a round skeleton frame with hoop- 
iron, or with wire-netting, for the body, neck, and head, 
and other thick parts. This metal skeleton must be 
built on and securely fixed to the main iron frame. The 
whole, or parts of the figure, may also be cored out with 
shavings or tow, and held in position with tar bands or 
canvas strips, dipped in plaster. Tow is an excellent 
material for forming cores. By making up the inner 
parts with dry tow, and then dipping tow in plaster for 


HOW TO USE THEM 


445 


the outside coat, the core can be made to any desired 
shape, and also leave the necessary thickness for the 
concrete. To prevent the material slipping down by 
its own weight, pieces of iron or wood, in the form of 
crosses, are fastened with copper wire or tar rope to 
the iron rods, which are used as single supports. These 
iron or wood pieces must be fixed in all directions, and 
in such a way that the material is held up by them. 
For small extremities, such as fingers of human figures, 
beaks of birds, fins of fishes, horns and tails of animals, 
iron rods should be fixed on the main frame, and the 
parts to be covered with cement must be notched or 
bound at intervals with copper wire or tar rope. The 
distance between the core and the finished face of the 
figure is of course the actual thickness of the model. 
This thickness may vary from 1 inch to 3 inches, or 
even 4 inches at some parts. An actual thickness of 2 
inches will be sufficient to give the requisite strength. 

When the core is made, cover it with a coat of Port¬ 
land cement and old lime putty, in the proportion of 3 
of the former to 1 of the latter, and add sufficient tow 
or hair to give tenacity. If there are open spaces in 
the skeleton iron work, bridge them over with bits of 
tiles and cement. The whole surface, after being coated, 
must be well scratched with a nail, to give a key for 
the roughing out coat. This scratched coat must be 
allowed to set before proceeding with the actual model¬ 
ling. The stuff for roughing out is composed of 2 
parts of Portland cement and 1 part of fine aggregate. 
Crushed bricks, stone, or pottery ware passed through 
a sieve having a % inch mesh may be used as aggre¬ 
gates. The finishing stuff is composed of fine sifted 
Portland cement. The addition of a fifth part of old 


446 


CEMENTS AND CONCRETES 


lime putty to the cement makes the stuff more mellow, 
and works freer and sweeter. The modelling is done as 
described for in situ work. The finishing coat can be 
colored to any desired tint, as already described. 

Concrete Fountainsj —Fine concrete is an excellent 
material for the construction of fountains. It is ob¬ 
vious that a vast amount of cutting and consequent 
waste of material is involved in the executing of foun¬ 
tains, 4 ‘ on the round, ’’ when natural stone is employed. 
Saving of material, and a corresponding reduction in 
the cost, is effected by use of a material that can be 
easily cast, and is at the same time durable and im¬ 
pervious. These qualities combined are found in arti¬ 
ficial stone composed of fine concrete. Being readily 
made in large blocks (any sized basin can be made in 
one piece), there is no jointing required, as is the case 
with terra cotta, which is another form of artificial 
stone. Fountains composed of fine concrete are made 
in a similar way to that described for making and cast¬ 
ing vases. 

Concrete Tanks .—Concrete tanks to contain water, 
and for a variety of manufacturing purposes, are now 
largely in use. They are strong and durable, and hav¬ 
ing hard smooth surfaces, they are easily washed and 
kept clean. Being impervious to vermin, damp, and 
atmospheric influences, they are the coolest and most 
sanitary water cisterns that can be used. Cattle troughs 
are best made in concrete. Concrete tanks have been 
used as water and silicate baths for indurating con¬ 
crete casts, and during their constant use for over a 
decade no signs of cracks or damp are visible. They 
were made in one piece, varying in size from 6 feet up 
to 18 feet long, 3 feet to 7 feet wide, 2 feet 6 inches to 


HOW TO USE THEM 


447 


4 feet high, and from 3 to 4% inches thick. Some were 
east, but the large ones were made in sitn. The method 
of construction (for in situ work) being simple and ex¬ 
peditious, the total cost is small. For a tank 9 feet long, 
4 feet 6 inches wide, 2 feet 6 inches high, and 3% inches 
thick, first frame up wood sides and ends to the above 
length, width, and height, then make inside boards,, 
the lengths and widths being the same as above, less 
the tank thickness, and the heights less the bottom 
thickness. The sides and ends are hung by means of 
cross battens laid on the upper edges of the outside 
framing, and kept in position with inside stays. This 
leaves an open and continuous space at the sides, ends, 
and bottom. The constructive materials are 1 part of 
Portland cement and 2 of fine slag or granite, gauged 
stiff, and laid over the bottom. Next, the open sides 
and ends are filled up, taking great care that the whole 
mass is thoroughly consolidated by ramming. The 
stuff for the sides and ends should be laid in layers 
from 6 to 8 inches deep, each layer being well rammed 
before the next is laid. 

The angles are strengthened by inserting angle irons 
during the process of filling in. As soon as the concrete 
is set the inner hoards are removed, and if the surface 
is smooth or dry, it must he keyed with a coarse drag 
or a sharp hand pick. It is then swept and wetted to 
cleanse it and stop the suction, so as to ensure perfect 
cohesion, and allow the final coat to retain its moisture 
during the process of trowelling and the stuff setting. 

The finishing coat is composed of neat cement, the 
finer ground the better, as percolation through con¬ 
crete made with a finely ground cement is less liable 
than when made with a coarsely ground cement. 


448 


CEMENTS AND CONCRETES 


The final coat is laid about 3/16 inch thick, and pre¬ 
ceded by brushing the surface' with liquid cement to 
fill up all crevices, and afford better adhesion between 
the surface and the final coat. When the stuff is firm, 
it is well trowelled to a fine and close surface. The 
outer boards are then removed, and the surface finished 
in a similar way. 

Concrete Sinks .—Concrete sinks can be made to any 
desired size or form. They are cast in wood or plaster 
moulds, and are composed of 1 part of Portland cement 
to 2 parts of fine crushed granite or other hard aggre¬ 
gate. They are made with rebated holes for traps. The 
ordinary size are as follows: 2 feet 6 inches by 1 foot 
8 inches; 2 feet 9 inches by 1 foot 8 inches; and 3 feet 
by 2 feet, all 6 inches deep, and from 2 to 3 inches thick. 

Garden Edging .—Plain and ornamented edgings are 
now made in concrete. They are made in various 
lengths. The most useful size is 3 feet long, 6 inches 
deep, and 2 inches thick. They can be made to any 
curve, and tinted to any shade. 

Concrete Vases .—During the last half-century thou¬ 
sands of vases, composed of fine concrete—commonly 
called “artificial stone”—have been used for the dec¬ 
oration of buildings and practical use in gardens, con¬ 
servatories, &c. For vases that are cast in sections the 
thickness of large and open parts, such as the “body,” 
are regulated by means of a plaster core, which is 
placed in the open mould. The contour of the core 
must be so arranged that the cast will draw from the 
core, or vice versa. For some forms of vases, the core 
must be made in pieces similar to a piece mould. The 
method of making, moulding, and casting—the latter 
by the aid of a template instead of a core 


HOW TO USE THEM 


449 


Concrete Mantel Pieces. —Chimney-pieces of all sizes 
and shapes are now extensively made in fine concrete. 
They are generally made in wood moulds, plaster 
moulds being let in the main mould for ornamental 
parts. They are often made in colored concrete. 

Colored Concrete .—Concrete casts, also work laid in 
situ, can be colored to imitate any natural stone. This 
is effected by mixing mineral oxides of the required 
color with the cement used for the surface coat. The 
color coat should not exceed % inch in thickness, as 
oxides are too expensive to use for the entire thickness 
of the cast. The quantity of oxide to be added to the 
cement depends upon the strength of the oxide. Some 
are much stronger than others. Five per cent, of a 
strong oxide will impart a close resemblance of the 
desired color to the concrete, hut a weak oxide will re¬ 
quire from 10 to 15 per cent., and even 20 per cent., to 
obtain the same color. Some of the red oxides range 
in color from scarlet or Turkey red, gradually deepen¬ 
ing to chocolate. Some oxides contain 95 per cent, of 
pure ferric oxide, wdiich is made from copperas, or, 
scientifically speaking, sulphate of iron. This is a by¬ 
product, and is frequently evolved from waste acid 
liquors at tinplate works, and is obtained in large quan¬ 
tities from South Wales. This kind of oxide is far 
more suitable for coloring concrete than ochres and 
most of the earthy oxides. Earthy colors, like Venetian 
red and umber, soon fade and have a sickly appearance. 
The oxides should be intimately mixed with the cement 
in a dry state before it is gauged. The mixing is gen¬ 
erally done by hand, but better results are obtained by 
the use of grinding machine. It is a safe plan to try 
various proportions of color and cement and gauge 


450 


CEMENTS AND CONCRETES 


small parts, and when set and dry select those most 
suitable for the desired purpose. All cast work, as soon 
as extracted from the moulds, should be examined, and 
any blubs stopped and chipped parts or other minor 
defects made good while the work is moist or green, 
using neat cement and colors in the same proportion 
as used for the surface stuff. Colored surfaces may be 
greatly improved by brushing the cast as soon as set 
with a solution of the same color as used for the sur¬ 
face coat. A color solution, made by mixing the color 
with water and a solution of alum, is very useful for 
coloring Portland cement, with or without sand. If this 
coloring solution is brushed over the surface while it 
is moist or semi-dry, a good standing color can be ob¬ 
tained without mixing color with dry cement. This 
method will be found useful for sgraffitto, &c. 

A novel and color-saving method, for coloring the 
upper surfaces of slabs or other flat casts, is effected 
by first filling in the mould in the usual way, then 
placing the colored cement in a dry state in. a hand 
sieve, and then violently shaking or tapping the sides 
of the sieve, so as to sprinkle the colored cement uni¬ 
formly over the surface until it is nearly 1/16 inch 
thick. The surface is then trowelled in the usual way. 
The sprinkling must be done as soon as the main body 
of the stuff is ruled off, so as to obtain a homogeneous 
body. Another and a novel method which may be ad¬ 
vantageously employed for finishing slab or other large 
surfaces in a mould is as follows: A fine finished face 
is more readily obtained by using a smoothing knife 
(for brevity termed a “shaver”) than by a trowel. A 
shaver is a piece of polished steel about 3 inches wide 
and % inch thick, the length being regulated according 


HOW TO USE THEM 


451 


to the width of the mould, and allowing about 8 inches 
at each end for handles. For instance, for a slab 2 feet 
wide, the shaver should be 3 feet long. This allows 2 
feet for the surface of the cast, 3 inches to bear on the 
rims of the mould, each 1 V 2 inches wide; 8 inches for 
the handles, each 4 inches long; and 1 inch for play. 
One edge or side is cut to an angle of 45°, so as to 
form a cutting edge. The method of filling in, coloring, 
and finishing the surface of the slab is as follows: First 
fill in the mould with the concrete, ramming and beat¬ 
ing it as already described until the stuff is about 1/16 
inch above the mould rims, then clean off the stuff on 
the rims with a wood template (rebated to fit the width 
of the rims), and lay the shaver flat on the rims, keep¬ 
ing the cutting edge outwards, and then push it for¬ 
ward, keeping it flat on the rims, so as to shave off the 
superfluous stuff. This done, sprinkle the colored ce¬ 
ment, with the aid of a sieve, until about 1/16 inch 
thick; then clean the rims again, and. pass the shaver 
forwards and backwards twice or thrice, which will 
leave a straight, smooth, and uniform-colored surface. 
This method effects a considerable saving in the amount 
of oxide and of time. The thickness of the coloring 
stratum is reduced mechanically to the minimum (about 
1/32 inch), which is all sufficient for coloring purposes 
where the surface is not subjected to frictional wear. 

As already mentioned, bullocks’ blood mixed with 
cement gives a near resemblance to red brick, but it is 
not a desirable material to work with, and the same 
effect can be obtained by the use of red oxides. Red 
sand, brick, and stone, all finely ground, have been em¬ 
ployed for coloring cement surfaces,, but if too fine or 
in large quantities they weaken the surface; and if 


452 


CEMENTS AND CONCRETES 


coarse-grained they possess little coloring effect, be¬ 
cause the particles are liable to show singly, causing a 
spotty appearance, or the cement entirely covers the 
surface of each particle of sand. Powdered glass, mar¬ 
ble, flint, alabaster, metal filings, and mineral coloring 
can be effectively employed for coloring concrete sur¬ 
faces by mixing with the cement used for the surface 
coat. The surface is improved by rubbing and stoning, 
also polishing, after the work is dry. Other methods 
and quantities of colors for coloring Portland cement 
surfaces are given. 

Fixing Blochs .—Concrete fixing blocks do not shrink, 
warp, or rot. Consequently they are superior to wood 
fillets, &c. They are principally used in concrete floors, 
stair landings, and walls, as bearings and fixing points 
for wire-lathing and fibrous plaster work. Floor boards 
may also be fixed to them. They are also built into 
brick walls for similar purposes, as well as for external 
wall tilings. For ceilings, stair soffits, and landings, 
the blocks are laid on the centrings where required, 
and permanently secured by laying concrete between 
and over them. For bearings and fixing flooring boards, 
they are secured flush. 

TYPICAL SYSTEMS OF REINFORCED CONCRETE 
CONSTRUCTIONS FROM VARIOUS SOURCES. 

Of the interesting features of modern civil engineer¬ 
ing, interesting because of their extreme novelty and 
successful application, reinforced concrete is probably 
most noteworthy because of its unique adaptability. 
How striking is the influence of steel reinforcement is 
best exemplified by a reference to Fig. 1. There tw') 


HOW TO USE THEM 


453 


beams are shown designed to carry ordinary floor loads, 
the one made entirely of concrete and the other of con¬ 
crete with a sheet of expanded metal imbedded in the 
tensile portion of the beam. The saving in mere weight 
of concrete alone is apparent; and when we remember 
that the adoption of floor beams entirely of concrete 
means an increase of thickness of nine inches or as¬ 
suming five to eight floors, an increase in the total 
height of the building (with extra cost and heavier 
walls, together with heavier foundations to carry them) 
of from four to six feet, we see that even as regards 
initial outlay for materials, the introduction of settle 
reinforcement into concrete construction is of import¬ 
ance. 

So far as economy in initial cost of materials is con¬ 
cerned, reinforced concrete is undoubtedly cheaper 
than either concrete or steel alone. It is not very easy 
to demonstrate this economy except by comparative 
cost in individual cases, but an approach to a systematic 
comparison has been made by Mr. Walter Loring Webb, 
as follows: A cubic foot of steel weighs 490 pounds. 
Assume as an average price that it can be bought and 
placed for 4.5 cents per pound. The steel will therefore 
cost $22.05 per cubic foot. On the basis that concrete 
may be placed for $6 per cubic yard, the concrete will 
cost 22 cents per cubic foot which is 1 per cent of the 
cost of the steel. Therefore, on this basis if it is neces¬ 
sary to use as reinforcement an amount of steel whose 
volume is in excess of 1 per cent of the additional con¬ 
crete which would do the same work, there is no econ* 
omy in the reinforcement, even though the reinforce¬ 
ment is .justified on account of the other considerations. 
Assuming 500 pounds per square inch as the working 


454 


CEMENTS AND CONCRETES 


compressive strength of concrete, and 16,000 as the per¬ 
missible stress in steel, it requires 3.125 per cent of steel 
to furnish the same compressive stress as-concrete. On 
the above basis of cost, the compression is evidently 
obtained much more cheaply in concrete than in steel 
—in fact, at less than one-third of the cost. On the 
other hand, even if we allow 50 pounds per square inch 
tension in the concrete and 16,000 pounds in the steel, 
it requires only 0.21 per cent of steel to furnish the 


*- 9 



Fig. 1.—These Beams Are Designed to Carry the Same 
Load. The Upper is of Reinforced Concrete, the 
Lower of Plain Concrete. 

same strength as the concrete, which shows that, no 
matter what may be the variation in the comparative 
price, of concrete and steel, steel always furnishes ten¬ 
sion at a far cheaper price than concrete, on the above 
basis at less than one-third of the cost. The practical 
meaning of this is, on the one hand, that a beam com¬ 
posed wholly of concrete is usually inadvisable, since its 
low tensile strength makes it uneconomical, if not actu¬ 
ally impracticable, for it may be readily shown that, 
beyond a comparatively short span, a concrete beam 
will not support its own weight. On the other hand, 




HOW TO USE THEM 


455 


on account of the cheaper compressive stress furnished 
by concrete, an all-steel beam is not so economical as 



Fig. 2.—Types of Steel Reinforcing Rods. 


a beam in which the concrete furnishes the compres¬ 
sive stress and the steel furnishes the tensile stress. 



Fig. 3.—A Reinforced Concrete Pier for Railway 
Traffic. 


This statement has been very frequently verified when 
comparing the cost of the construction of floors de- 













456 


CEMENTS AND CONCRETES 


signed by using steel I-beams supporting a fire-proof 
concrete floor, and that of a concrete floor having a 
similar floor slab but making the beams as T-beams of 
reinforced concrete. 

A good idea of reinforced concrete construction can 
be obtained from Fig. 3, which is an isometrical pro¬ 
jection of a portion of a pier strong enough to carry 
the heaviest railway traffic. The disposition of the 
steel work is shown in the piles, the main girders, and 
beams; and the manner in which the steel rods run¬ 
ning along the tensile or bottom side of the girders 
and beams are bent up over the top of the pile, which 
is here the tensile member (the beams being continu¬ 
ous), and then down again to the bottom of the girders 
and beams, is most instructive. 



Fig. 4.—Method of Joining Columns and Floors. 

The sections of the steel employed vary in different 
systems, being round, flat, square, angle, and tee—Fig. 
2. In all cases the simplest section is the best, as it 
costs less, and readily allows the concrete to be rammed 
into the closest contact with the entire surface of the 
armoring. In America the Ransome system is most 
extensively used—a system in which a bar of twisted 





HOW TO USE THEM 


457 


steel is employed. Small sections are better than large 
ones, for by their use we obtain a more uniform dis¬ 
tribution of stress in the steel; we can also readily 
bend and work them into any required shape; and 
finally the most economical disposition of material is 
obtained, the metal being placed at the maximum dis¬ 
tance from the neutral axis. 



Fig. 5.—The Monier System. 


Expanded metal meshing (Fig. 6) is increasingly em¬ 
ployed, more particularly in the lighter forms of con¬ 
struction. It consists of sheets of metal which have 
been mechanically slit and expanded, so as to produce 
a network. This type of reinforcement has many and 
obvious advantages. Its mere existence is proof of good 
steel, and it forms an excellent key for concrete too 
thin to permit reinforcement in the form of rods; thus 
it is very useful for concrete plaster, ceiling, and parti¬ 
tion wall work. A good example of reinforced con¬ 
crete in which expanded metal is used may be found 
in the Monier system (Fig. 5). An improvement on 




458 


CEMENTS AND CONCRETES 


this system is the Clinton method (Fig. 11) of using 
an electrically welded wire netting in combination with 
concrete. Clinton fabric consists of drawn wire of 6 
to 10 gauge, which may he made in lengths up to 300 
feet. The system is therefore a continuous bond system, 
which prevents the entire collapse of a span unless the 
weight imposed is sufficient to break all the wires. 



Fig. 67 —Expanded Metal. 


Columns and Piles .—Reinforced columns are made 
with either square, rectangular, or circular sections. 
They are reinforced with from four to twenty rods, the 
diameters of which vary from % to 2% inches. The 
rods are placed as nearly as practicable to the circum¬ 
ference of the column, so as to give the greatest radius 
of gyration for the section; hut they are never placed 
so near the surface that they have not at least one or 
two inches protective covering. The steel so disposed 
is able to take up the tensile stresses which may be 



HOW TO USE THEM 


459 


induced in the column by eccentric loading, lateral 
shock, wind pressure, and the pull of belting. 

Columns and piles are made in wooden boxes, each 
consisting of three permanent sides and a fourth side 
which is temporary and removable. Under the patent 
rights of Francois Hennebique the reinforcing is placed 



Jj'ig. 7. -Eaosome System of Erecting Columns. 


in these boxes, and adjusted by gauges to within one or 
two inches of the sides. The concrete is laid and 
rammed, about six inches at a time, with small hand 
rammers. The open side of the box is built up by 
battens fitting into grooves in the permanent sides, as 
the work proceeds; this enables inspection of the work 























460 


CEMENTS AND CONCRETES 


to be made, and facilitates the placing of the ties at the 
proper positions. The ties are made of round wire 3/16 



Fig. 8.—Wood Centering and Ransome Steel Bars for 50-foot 
Floor Span* 


inch diameter and are dropped down over the top of 
the steel rods. They are spaced down two-inch centres 











































HOW TO USE THEM 


461 


at the bottom and top, to twelve-inch centres in the 
centre of length of the column, and are intended to 
prevent the steel rods from spreading out under the 
action of longitudinal loads. Fig. 4 shows the method 
of joining columns to the floor. 



Fig, 9.—Concrete Power Plant in Course of 
Construction. 


In the Ransome columns as exemplified in a recently 
constructed factory building (Fig. 7), the vertical re¬ 
inforcement consists of round rods with the connections 
made about 12 inches above the floor line; in order that 







462 


CEMENTS AND CONCRETES 


these rods might be continuous the ends were threaded 
and connected with sleeve nuts, thereby developing the 
full strength of the rods. Horizontal reinforcement 
was also used, consisting of hoops formed by a spiral 



Fig. 10*—Slabs of Concrete Ready for Roof. 


made from 44 inch diameter soft wire, having a pitch 
or spacing of 4 inches in the basement columns, and 
gradually increasing to a pitch of 6 inches in the top 
story (Fig. 12). 

According to Mr. Henry Longcope the first innova¬ 
tion in concrete piles was the sand pile, produced by 





HCTW to use them 


463 


driving a wooden form in the 
ground and withdrawing it, 
the hole being filled with 
moist sand well rammed. The 
next method adopted was to 
drive a metal form into the 
ground and after withdrawal 
to fill the hole with concrete. 
This was not successful, as it 
was open to the serious objec¬ 
tion that on withdrawing the 
form, the ground would col¬ 
lapse before the concrete could 
be inserted. Still another 
method was introduced, which 
consisted in dropping a cone- 
shaped five ton weight a num¬ 
ber of times from a consider¬ 
able height, in order to form 
a hole, which was afterward 
filled with concrete. This 
method never passed the ex¬ 
perimental stage. Coming to 
more successful systems we 
may mention a method of 
moulding a pile of concrete, 
allowing it to stand, and then 
driving it into the ground, a 
cap being used to protect the 
head. 

Of modern systems which 
have proven successful, Gil- 
breth’s pile must first be re- 



Fig. 11.—Clinton System Using Electrically Welded Fabric. 







Fiff. 12.—Ransome Floor System With Beams. 
















































HOW TO USE THEM 


465 


corded. Gilbreth used a molded corrugated taper pile, 
cast with core hole the entire length of the pile, which is 
jetted down by a water jet and finally settled by hammer 
blows. 

Features which recommended the Gilbreth piles are 
the opportunities for complete inspection before driv¬ 
ing and the fact that they save time because they can 
be cased while excavation is going on. After being 
driven they can be loaded immediately. Naturally they 
present considerable skin friction. The making of these 
piles above the ground surface also does away with the 
possibility of their being damaged or squeezed out of 
shape by the jar occasioned by driving forms for ad¬ 
joining piles. 

Still another method is used by Raymond. Under 
this system piles are usually put in by either of two 
methods, the jetting method or the pile core method. 
The water jet system is used only where the material 
penetrated is sand, quicksand, or soft material that will 
dissolve and flow up inside the pile when the water is 
forced through the pipe, thus causing the shell to settle 
until it comes in contact with the next shell, and so on 
until the desired depth has been reached. The shells 
are filled with concrete simultaneously with the sinking 
process, and when necessary spreads are attached to 
keep the hole in perfect line with the pipe. The % 
inch pipe is left in the centre of the pile and gives it 
greatly increased lateral strength. If desired, the 
lateral strength may be further increased by inserting 
rods near the outer surface of the concrete. By this 
method, piles of any size up to two feet in diameter at 
the bottom and four feet at the top can be put through 


466 


CEMENTS AND CONCRETES 


any depth of water and to a suitable penetration in 
sand or silt (water sediment). 

The pile-core method is the one most generally used 
for foundation work and consists of a collapsible steel 
pile core, conical in shape, which is incased in a thin, 
tight-fitting metal shell. The core and shell are driven 
into the ground by means of a pile driver. The core 
is so constructed that when the desired depth has been 
reached it is collapsed and loses contact with the shell, 
so that it is easily withdrawn, leaving the shell or cas¬ 
ing in the ground, to act as a mold or form for the 
concrete. When the form is withdrawn, the shell or 
casing is filled with carefully mixed Portland cement 
concrete, which is thoroughly tamped during the filling 
process. 

The simplex system uses another method in which 
the driving form consists of a strong steel tube, the 
lower end of which is fitted with powerful tooth jaws, 
which close together tightly, with a point capable of 
opening automatically to the full diameter of the tube 
while being withdrawn. The point of the form closely 
resembles the jaws of an alligator. At the same time 
the form is being withdrawn, the concrete is deposited. 

It is so evident that concrete is vastly superior to 
wood in the construction of piles that it is almost su¬ 
perfluous to mention the points of superiority. Con¬ 
crete is not subject to rot or the ravages of the teredo 
worm, neither can the piles constructed of concrete be 
destroyed by fire, and no cost is attached for repairs. 
While it is not possible to give accurate statistics as to 
the life of a wooden pile, as it varies so much under 
different conditions, yet we know that in some cases 
a wooden pile is rendered worthless in a very few years, 


HOW TO USE THEM 


467 


especially when the surrounding material is composed 
of rotted vegetation, or wdiere the pile is exposed by 
the rise and fall of tides. It is also impossible to state 
the exact cost of a concrete pile, as it varies also ac¬ 
cording to conditions. Ordinarily speaking; a concrete 
pile will cost from one and one-half times or two times 
as much as a wooden pile; but in order to illustrate 
where a saving can be made, the following extract is 
given from a report on the piles driven at the United 
States Naval Academy at Annapolis, Md.: 

“The original plans called for 3,200 wooden piles 
cut off below low water with a capping of concrete. 
To get down to the low water level required sheet pil¬ 
ing, shorting and pumping, and the excavating of near¬ 
ly 5,000 cubic yards of earth. By substituting concrete 
piles, the work was reduced to driving 850 concrete 
piles, excavating 1,000 cubic yards of earth and placing 
of 1,000 cubic yards of concrete.” 

In the work mentioned, the first estimate for wooden 
piles placed the cost at $9.50 each, while the estimate 
for concrete piles was placed at $20 each, yet the esti¬ 
mate based on the use of wood piles aggregated $52,840, 
while the estimate based on the use of concrete piles 
was $25,403, or a total saving in favor of concrete of 
over $27,000. 

In several instances piles have been uncovered to 
their full depth, and they were found to be perfectly 
sound in every particular. By surrounding the opera¬ 
tion with the safeguards provided, it is almost impos¬ 
sible to make a faulty pile. The concrete is made as 
wet as good practice will allow. Constant ramming and 
dropping the concrete from a considerable height tend 
to the assurance of a solid mass, then the target on 


468 


CEMENTS AND CONCRETES 


the ramming line or the introduction of an electric light 
into the form shows what is being done at the bottom 
of the form. 

Floors, Slabs and Roofs .—The system of construction 
for floors, slabs, and roofs is determined by the extent 
of the work and the nature of the loads to be carried. 
If intended for small buildings and offices, the items 
can be made before erection (Figs. 9 and 10); but in 
the case of warehouses, factories, piers, and jetties, 
where live loads and vibrator stresses have to be borne, 
a monolithic structure is secured by building in molds 
directly on the site. For the lighter classes of mono¬ 
lithic structure, expanded metal is admirably suitable; 
it is also much used for the roofs of reservoirs, and for 
thin partitioned walls. The meshing is simply laid 
over the ribs or floor beams, which have been already 
erected, and the green concrete is applied to the acquired 
thickness, being supported from below by suitable sup¬ 
porting work, which is removed as soon as the concrete 
has set. In cold storage factories, the floor beams and 
ceilings are invariably erected first, the floor being laid 
afterward. The ceiling is then solid with the floor 
beams on their under side, and the floor is solid with 
them on their upper side, the air space between being a 
great aid to the maintenance of a low temperature for 
refrigeration. 

In the Monier floors the reinforcement consists of 
round rods varying from % inch to % inch diameter. 
The rods are spaced at about six times their diameter, 
and are crossed at right angles, being connected by 
iron wire bound round them. This artificial method of 
securing the rods takes considerable time, and is thus 
a somewhat costly process. To produce continuity of 


HOW TO USE THEM 


469 


metal, the different lengths of rods are overlapped for 
about 8 to 16 inches, and bound with wire. 

The Schluter are similar to the Monier floors, but 
the rods are crossed diagonally, and the longitudinal 
rods are of the same size as the transverse ones. The 
Cottancin floors have their rods interlaced like the 
canes of a chair seat or a basket, and the Hyatt floors 
have square rods with holes through which small trans¬ 
verse rods pass. Over fifty systems of reinforcing are 
in use, and in most cases the only points of difference 
are the shape of the section and the method of attach¬ 
ment and adjustment. 

Beams .—It is obvious that, as the span increases, a 
limit will soon be reached beyond which it is not eco¬ 
nomical to use plain floor slabs, for their dead weight 
becomes of such magnitude as to prohibit their use. We 
have thus to resort to a division of the main span by 
cross beams resting on columns, and the floor is laid 
on these beams, which are arranged to take as much of 
the load as to render it possible to reduce the thick¬ 
ness of the floor within reasonable limits. Reinforced 
concrete beams are typical of the construction in which 
the merits of two component materials are made to 
serve a common end; but in the particular case of steel 
and concrete, the actual part played by the steel is 
not at all well understood. 

Speaking generally, beams do not differ in construc¬ 
tional details from floors. The same reinforcement is 
used in both, the only difference being, that as beams 
are usually deeper than floors, the shearing stresses be¬ 
come more pronounced, the greater provision has to be 
made for them by a liberal use of stirrups or vertical 
binding rods. In some systems the reinforcement con- 


470 


CEMENTS AND CONCRETES 


sists entirely of straight rods, disposed in any part of 
the beam where tensile stresses are likely to be called 
into play. In others, specially bent rods are joined or 
welded to straight rods, disposed and when welding has 
to be done it would appear that wrought iron is more 
suitable than steel. 

It is usual to arrange the dimensions of the beams 
so that the whole of the compressive stresses are taken 
by that portion of the concrete on one side of the neu¬ 
tral axis; but in some cases, as with continuous beams 
or heavy beams of small depth, a portion of the rein¬ 
forcement is disturbed along compressed portion of the 
beam, the steel rods either taking up the excess of 
compressive stress over that at which the concrete can 
be safely worked, or else taking up the tensile stresses 
at the places where they occur over the supports. As 
a general rule we may take it that the economical depth 
for a reinforced concrete beam, freely supported at 
both ends, is one-twentieth the span, and is thus ap¬ 
proximately the same as that of a steel girder of equal 
strength. Reinforced concrete beams are now made for 
spans up to 100 feet for buildings, and 150 feet for 
bridges. But for each class of work beyond this limit, 
the weight becomes excessive. Several arched ribs, 
for much greater spans havej however, been success¬ 
fully built. 

The beams are made in much the same way as piles 
and columns; they can be made in sheds on the site, 
or in the actual position they are to occupy when fin¬ 
ished. The ceiling and beams are erected first, the 
floor being afterward worked on the top of the beams. 
We thus obtain a very perfect monolithic structure in 
which any vibration set up by machinery, falling loads, 


HOW TO USE THEM 


471 


etc., will be of much less extent than with any ordinary 
type of building, in which there is often a‘ great want 
of rigidity, the beams and arches being loose and able 
to vibrate independently of other parts of the struc¬ 
ture. 

Concrete being as weak in shear as in tension, pro¬ 
vision is also required to take the shearing stresses. 
Some American designers have to this end patented 
special forms of reinforcement bar, in which each main 
tension bar has projecting upward from it ties inclined 
at the angle of 45 deg. (Kahn system.) These ex¬ 
tend to the top of the bar and take the tensile stresses 
arising from the shear. The corresponding compres¬ 
sive stress at right angles to this is carried by the con¬ 
crete. The system is efficient and on large spans, where 
weight must be reduced to a minimum, it has its ad¬ 
vantages. 

Thus, in the Ransome system (Fig. 12), the shearing 
stresses at the end of a beam are taken up by inclined 
reinforcing rods imbedded in the concrete at the junc¬ 
tion of beam with column. 

Arches .—Concrete has long had an extensive ap¬ 
plication in the building of arches, but until the in¬ 
troduction of reinforced concrete the arches that could 
be economically and safely constructed were limited to 
spans of a few feet. The general rule that the line of 
resistance fell within the middle third had to be ob¬ 
served for simple concrete arches, as for those in brick¬ 
work and masonry; and the thickness of the arches 
at the crown was thus approximately the same whether 
built in either of these materials. The introduction of 
steel reinforcement, however, made it possible not only 
to reduce the thickness of the ring of a given load- 


472 


CEMENTS AND CONCRETES 



Types of Reinforced Concrete Arches. 






























HOW TO USE THEM 


carrying capacity, but by suitably providing for rue 
tensile stresses to enable arches of much greater span 
and smaller rise to be built. Some general types of 
arches in reinforced concrete are shown in Figs. 13, 14, 
15 and 16. Fig. 13 shows an ordinary arch with top 
and bottom armature. In many cases where the ten¬ 
sile stresses can safely be carried by the concrete the 
top armature can be omitted. In the Melane arches, 
shown in Fig. 14, the top and bottom armatures are 
connected by ligatures, and in the Hennebique arches 
(Fig. 15) stirrups are used. As a general rule, hinges 
should be built at the stringings and the crown, for the 
calculations are much simplified, and the line of re¬ 
sistance goes through the hinges; the arches also ad¬ 
just themselves better to the load and to any slow 
temperature changes, and when the centering is struck 
the arch can better take its bearings without cracking. 
The methods of calculations for arches are as numer¬ 
ous as those for beams, and generally speaking are as 
irrational. The Monier system is the one most gen¬ 
erally adopted, and over 400 bridges built on this sys¬ 
tem now exist in Europe. In America expanded metal 
and Clinton electrically-welded fabric are often used. 
An example of the latter construction will be found in 
Fig. 17. 


SOME MISCELLANEOUS ITEMS. 


Lintels .—Concrete lintels and beams are fast super¬ 
seding those made of stone and wood. Lintels are 
generally cast and then fixed. 


474 


CEMENTS AND CONCRETES 



A Spiral Staircase built on the HennebiQue 
principle. 





HOW TO USE THEM 


475 


Concrete Walls .—Many ingenious plans have been 
introduced as substitutes for wood framing for retain¬ 
ing concrete while constructing walls and partitions. 
The most simple method is as follows: Cast a number 
of concrete angle slabs with an L section, and then 
place them level in contrary directions, thus .[ [, 
spaced to the width of the proposed partition or wall 
until the desired length of wall is completed, and fill 
the openings with rough concrete. When set, place 
another row on this (taking care to break the joints by 
overlapping), and so on, until the desired height is 
obtained. Concrete for walls formed in situ should be 
deposited in layers, taking care that each layer is thor¬ 
oughly rammed and keyed, as described under the 
heading of 1 ‘Ramming.” A suitable finish for ordi¬ 
nary purposes, for rough walls built in situ, may be 
obtained by “rough trowelling.” This is done by 
first gauging 1 part of Portland cement, 1 part of old 
lime putty, and 2 parts of sand. The adding of lime 
renders the stuff more plastic and easy to work, with¬ 
out decreasing the impermeability of the work. This 
“limed cement” is applied with a hand-float, and is 
thoroughly worked into the crevices of the concrete, 
but leaving no body on the surface. The surface is 
then finished by brushing with a wet stock-brush. The 
walls should be well wetted before the stuff is applied. 

Strong Rooms .—Concrete is frequently employed in 
the construction of strong-rooms that are situated 
underground, and are rendered damp-proof as well as 
burglar-proof, which is useful for the storage of docu¬ 
ments. 

Concrete Coffins and Cementation .—The great im¬ 
provements in the manufacture of Portland cement 


476 


CEMENTS AND CONCRETES 


during the last decade has so cheapened and improved 
the quality as to bring it more and more to the front 
as one of the most useful and important materials for 
a variety of purposes. One of the latest uses found for 
it is in the construction of coffins, by the author, whose 
invented and registered idea was that such a coffin, 
made of specially prepared metallic concrete, would 
be impermeable, and practically indestructible, and 
that it would obviate the danger of spreading the 
poisons of disease by preventing the escape of noxious 
gases. The lid having a strong piece of plate glass 
embedded in the concrete, and directly over the face, 
enabled the mourners to see the features of the depart¬ 
ed. The edge of the open coffin had a sunk groove, 
and the lid a corresponding projection, only smaller, 
to allow for a coat of tine cement. When the joints 
were bedded and pressed together until the excess ce¬ 
ment oozed out, the coffin was hermetically sealed. 
The coffin should be left uncovered by cement for 
identification, and so that friends could view it until 
the time of removal to the cemetery. The face could 
then be covered with quick-setting cement, which, join¬ 
ing with the other portion of cement, would perma¬ 
nently embalm the body, which would further be pro¬ 
tected by fixing the lid in a similar way. If the prop¬ 
erties of this class of coffin are taken into considera¬ 
tion, the expense will be comparatively less than that of 
wood. If expense is not a special consideration, the 
coffin can be enriched with armorial bearings or other 
devices. The concrete may also be polished like real 
granite. One objection was raised as to the weight, 
but the old stone coffins and those of oak lined with 
lead were also heavy. Besides, the weight would bft 


HOW TO USE THEM 


477 


a protection against body-snatchers, and bearing in 
mind that a coffin is only moved about once in a life¬ 
time, or rather at death, the question of weight is un¬ 
important. Cementation, from a sanitary point of 
view, would be equal if not superior to cremation. In 
case of an epidemic, the coffins could be cemented at 
once, and stacked in the cemetery until graves or vaults 
were prepared for them. It may be safely said that it 
is a clean, safe, effectual, rapid and sanitary method 
of disposing of the dead. If their manufacture should 
not cause any great amount of extra employment for 
plasterers, the latter can at least make their own cof¬ 
fins, in frosty weather, when most works are stopped, 
and they could use them as baths during their life¬ 
time. 

Stonette .—Stonette is a composition of Portland ce¬ 
ment and fine aggregate, to imitate any kind of stone, 
and so made that it can be carved the same as natural 
stone. The Portland cement must be thoroughly air- 
slaked, finely sifted, and gauged with the natural ag¬ 
gregate in the proportion of 2 of cement to 7 of ag¬ 
gregate. The aggregate is composed of finely crushed 
natural stone, the same as that to be imitated. This 
should be passed through a fine sieve. It is necessary, 
when imitating some stones, to add a small portion of 
oxide to counteract the color of the cement. If a very 
white stone is being imitated, the addition of a small 
proportion of whiting or French chalk or well-slaked 
white limestone, is necessary to obtain the desired 
color. The material should be gauged stiff, and then 
well rammed into the mould. The carving is best done 
while the cast blocks are green. 

Tile Fixing .—Tile fixing is in some places a sepa- 


478 


CEMENTS AND CONCRETES 


rate branch of the building trade, but it is generally 
recruited from the ranks of plasterers, and in some 
districts it is done by plasterers. As regards the pro¬ 
cess of placing the tiles, it is best to work from the 
centre of the space, and if the design be intricate, to 
lay out a portion of the pavement according to the 
plan, upon a smooth floor, fitting the tiles together 
as they are to be laid. Lines being stretched over the 
foundation at right angles, the fixing may proceed, 
both the tiles and the foundation being previously 
soaked in cold water, to prevent the too rapid dry¬ 
ing of the cement, and to secure better adhesion. The 
border should be left until the last. Its position and 
that of the tiles are to be obtained from the drawing, 
or by measuring the tiles when laid loosely upon the 
floor. The cement for fixing should be mixed thin, in 
small quantities, and without sand. It is best to float 
the tiles to their places, so as to exclude air, and fill 
the spaces between them and the foundation. For fix¬ 
ing tiles in grate cheeks, sides and backs of fire-places, 
etc., equal parts of sand, plaster and hair mortar may 
be used. These materials are sometimes mixed with 
hot glue to the consistency of mortar. The tiles should 
be well soaked in warm water. Keen’s or other white 
cements are used as fixing materials for wall tiles, neat 
Portland Cement (very often killed) being generally 
used for floor work. Tiles may be cut in the follow¬ 
ing manner: Draw a line with a pencil or sharp point 
where the break is desired, then placing the tile on a 
form board, or embedding it in sand on a flagstone, 
tap it moderately with a sharp chisel and a hammer 
along the line, up and down, or scratch it with a file. 
Tho tile may then be broken in the hand by a gentle 


HOW TO USE THEM 


479 


blow at the back. The edges, if required, may be 
smoothed by grinding or by rubbing with sand and 
water on a flat stone. Tiles may also be sawn to any 
desired size. Cement should not be allowed to harden 
upon the surface of the tile if it can be prevented, as 
it is difficult to remove it after it has set. Stains or 
dirt adhering to tiles may be removed by wetting with 
diluted muriatic acid (“spirits of salts”), care being 
taken that the acid is all wiped off, and, after wash¬ 
ing, the superfluous moisture must be wiped off with 
a clean, dry cloth. In order to obtain a sound and 
straight foundation, which is imperative for good per¬ 
manent tile fixing, the substratum, whether on walls or 
floors, should be composed of Portland cement gauged 
with strong sand or similar aggregate in proportion 
of 1 of the former to 3 of the latter. The surface must 
be ruled fair and left rough, so as to form a fair bed 
and key for the fixing materials and tiles. 

Setting Floor and Wall Tile .—As this work properly 
belongs to the plasterer, where no regular tile setter is 
available, I have thought it proper to publish the fol¬ 
lowing instructions for doing this work, which are 
taken from a treatise prepared for the Tile Manufac¬ 
turers of the United States. This treatise, in pamphlet 
form, was intended for distribution among buyers and 
workers in tiles, and the directions and suggestions 
laid down in it are of the best, and quite suited to the 
wants of the workingmen: 

Foundations—A good foundation is always neces¬ 
sary, and should be both solid and perfectly level. Tile 
should always be laid upon concrete foundation, pre¬ 
pared from the best quality of Portland cement and 
clean, sharp sand and gravel, or other hard material. 


480 


CEMENTS AND CONCRETES 


(Cinders should never be used, as they have a tendency 
to destroy the life of the cement and cause it to dis¬ 
integrate.) A foundation, however, may also be formed 
of brick or hollow tile embedded solidly in and covered 
with cement mortar. Concrete should be allowed to 
thoroughly harden before laying the floor, and should 
be well soaked with water before laying the tile. 

Lime mortar should never be mixed with concreting. 

Concrete should consist of one part Portland cement, 
two parts clean sharp sand, two parts clean gravel, 
and thoroughly mixed with sufficient water to form a 
hard, solid mass when well beaten down into a bed, 
which should be from 2 y 2 inches to 3 inches thick. If 
the concrete bed can be made over three inches in 
thickness, the concrete can then be made of one part 
Louisville cement, one part clean sharp sand, one part 
clean gravel and thoroughly mixed with sufficient wa¬ 
ter, as above described. * 

For Floors. —The surface of the concrete must be 
level and finished to within one (1) inch of the fin¬ 
ished floor line, when tile % inch thick is used, which 
will leave a space of % inch for cement mortar, com¬ 
posed of equal parts of the very best quality Portland 
cement and clean sharp sand. The distance below 
the surface of the finished floor line, however, should 
be governed by the thickness of the tile. 

For Wood Floors. —When tiles are to be laid on wood 
flooring in new buildings the joists should be set five 
inches below the intended finished floor line and spaced 
about 12 inches apart and thoroughly bridged, so as to 
make a stiff floor, and covered with one-inch boards 
not over six inches wide (boards three inches wide 
preferred), and thoroughly nailed, and the joints % 


HOW TO USE THEM 


481 


inch apart to allow for swelling. (See No. 31.) (A 
layer of heavy tar paper on top of wood flooring will 
protect the boards from the moisture of the concrete, 
and will also prevent any moisture from dripping 
through to a ceiling below.) , 



In Old Buildings .—Cleats are nailed to joists five 
inches below the intended finished floor line, and short 
pieces of boards % inch apart fitted in between the 



joists upon the cleats and well nailed, and the joists 
thoroughly bridged. The corners on the upper edge 
of the joists should be chamfered off to a sharp point 
(see Fig. 32), as the flat surface of the joists will give 
an uneven foundation. When the strength of the 
joists will permit, it is best to cut an inch or more off 



























482 


CEMENTS AND CONCRETES 


the top. (Where joists are too weak, strengthen by 
thoroughly nailing cleats six inches wide full length 
of joists.) When the solid wood foundation is thus 
prepared, concrete is placed upon it as above directed. 

Where Steel Beams and hollow tile arches are used, 
frequently very little space is left for preparing a 
proper foundation for setting tile, as the rough coating 
is usually put in by the hollow tile contractor to pro¬ 
tect his work, but this covering should always conform 



? CtM£M* 

J .coA/cncrs 


Fig. 33. 


to the requirements for a solid tile foundation. Should 
this not be the case, the tile contractor should remove 
sufficient of the covering to allow him to put down a 
foundation that will insure a satisfactory tile floor. 
(Cinders, lime, mortar or inferior material must never 
be used.) 

The tops of iron beams should be from three to four 
inches below ihe finished floor line, to prevent floors, 
when finished, showing lines of the beams. 

For Hearths. —The foundation for hearths should be 
placed upon a brick arch, if possible, to ensure perfect 
fire protection, and then covered with concrete in the 
same manner as directed for tile floors. If placed 
upon a sub-foundation of wood, the concreting should 
be at least six inches thick. (See Figs. 34 and 35.) 













HOW TO USE THEM 


480 






















































































484 


CEMENTS AND CONCRETES 


For Walls .—When tiles are to be laid on old brick 
walls the plaster must be all removed and the mortar 
raked out of the joints of the brick work to form a key 
for the cement. On new brick walls' the points should 
not be pointed. When tiles are to be placed on stud¬ 
ding, the studding should be well braced by filling 
in between the studding with brick set in mortar to the 
height of tile work (see Fig. 36); or brick work may be 
omitted and extra studding put in and thoroughly 



Fig. 36. 


bridged, so as to have as little spring as possible, and 
this studding then covered with sheet metal lathing. 
(See Fig. 37.) (Tile must never be placed on wood lath 

or on old plaster.) The brick walls must be well wet 
with water and then covered with a rough coating 
of cement mortar, composed of one part Portland ce- 































































HOW TO USE THEM 


485 


ment and two parts clean sharp sand. When tiles are 
placed on metal lathing, hair should be mixed with the 
cement mortar to make it adhere more closely to the 
lath. The cement mortar should be % inch thick, or 
sufficient to make an even and true surface to within 
one (1) inch of the intended finished surface of the 
tile, when tile % inch thick is used, which will allow 



a'space of % inch for the cement mortar, composed as 
above for rough coating the walls. The face of the 
cement foundation should be roughly scratched and 
allowed to harden for at least one day before com¬ 
mencing to lay the tile. If any lime is mixed with the 
cement mortar for setting the tiles, it should never 
exceed 10 per cent., and great care must be used to 
have the lime well slaked, and made free from all 


















































486 


CEMENTS AND CONCRETES 


lumps by running through a coarse sieve, in order to 
guard against “heaving” or “swelling,” and thus 
loosening or “lifting” the tiles. 

Important .—The foundation for both floor and wall 
tiling should be thoroughly brushed, to remove all dust 
and small particles adhering to it, and then well wet 
before putting on the cement mortar. To ensure a 
perfect bond it is best to coat the foundation by brush¬ 
ing over it pure cement mixed in water. 

Cement .—The very best quality of Portland cement 
should always be used for setting either floor or wall 
tile and for grouting the floors, and the very best 
quality of Keene’s Imported Cement for filling the 
joints in the wall tiling. 

Sand.— Clean, sharp grit sand, free from all salt, 
loam or other matter, and perfectly screened before 
mixing with the cement, should always be used. 

Mortar .—For floors or vitrecus tiles, should be com¬ 
posed of equal parts of cement and sand, and for wall 
tiles one (1) part of cement md two (2) parts sand. 
The mortar should not be too wot, but should be rather 
stiff, and should always be used c resh, as mortar, when 
allowed to set before using, loses a portion of its 
strength. 

Soaking .—Tiles must always be thoroughly soaked 
in water before setting, which makes the cement unite 
to the tiles. 

The Tiles for the Floors are first laid out to ascer¬ 
tain if they are all right and compared with the plan 
provided for laying the floors. Strips are then set, 
beginning at one end of and in the centre of the room, 
and level with the intended finished floor line. Two 
sets of guide strips running parallel about 18 to 30 


HOW TO USE THEM 


487 


inches apart should be set first. (See Fig. 38.) The 
mortar is then spread between them for about six to 
ten feet at a time, and level with a screed notched at 
each end, to allow for the thickness of the tiles. The 
tiles are placed upon the mortar, which must be stiff 
enough to prevent the mortar from working up be¬ 



tween the joints. The tiles are to be firmly pressed 
into the mortar and tamped down with a block and 
hammer until they are exactly level with the strips. 
When the space between the strips is completed, the 
strips on one side of the tile is moved out 18 to 30 
inches and placed in proper position for laying an¬ 
other section of tile, using the tiles which have been 





















488 


CEMENTS AND CONCRETES 


laid for one end of the screed, and the laying of the 
tile continued in the same manner until the floor is 
finished. When the cement is sufficiently set, which 
should be in about two days, the floor should be well 
scrubbed with clean water and a broom, and the joints 
thoroughly grouted with pure cement (mixed with 
water to the consistency, of cream). As soon as this 
begins to stiffen, it must be carefully rubbed off with 
sawdust or fine shavings and the floor left perfectly 
clean. 

Ceramics .—The foundation and cement mortar for 
ceramics are the same as for plain or vitreous floors, 
and the guide strips used in the same manner. The 
cement mortar is then spread evenly and the tile sheets 
laid carefully on it with the paper side up. After the 
batch is covered, the tile setter should commence to 
press the tile into the mortar, gently at first, firmly 
afterwards, using block and hammer, thus leveling 
the tile as correctly as possible. The tile should be 
beaten down until the mortar is visible in the joints 
through the paper; however, without breaking it. The 
paper is then moistened, and after it is well soaked 
and can be easily removed, it is pulled off backwards, 
starting from a comer. After removing the paper, the 
tile should be sprinkled with white sand before fin¬ 
ishing the beating, so that the tiles will not adhere to 
the beater, owing to the paste which is used in mount¬ 
ing them. Corrections of the surface are then made 
by leveling it with block and hammer. The filling of 
the joints and cleaning of the surface is a delicate op¬ 
eration, as the looks of this work depends largely upon 
it. The joints are to be filled with clean Portland 
cement mixed with water. This mixture is forced into 


HOW TO USE THEM 


489 


the joints with a flat trowel (not with a broom, which 
often scrapes out the joints). After the joints are 



filled, the surplus cement is removed from the sur¬ 
face by drawing a wet piece of canton flannel over it. 



This piece of cloth must be washed out frequently with 
Mean, water. After the floor is cleaned, it should be 























































490 


CEMENTS AND CONCRETES 


allowed to stand for a day or two, when the whole 
floor is to he rubbed with sharp sand and a board of 
soft lumber. This treatment, which the last traces of 
cement, is preferable to the washing off with an acid 
solution, as it will not attack the cement in the joints. 
In laying the tile sheets on the cement, care should be 
taken to have the widths of joints spaced the same as 
the tile on the sheets to prevent the floor having a block 
appearance. 



The Tiles for the Walls or Wainscoting are first laid 
out and compared with the plan provided for setting 
them. Guide strips are then placed on the wall paral¬ 
lel and about two feet apart, the bottom one being so 












































HOW TO USE THEM 


491 


arranged as to allow the base to be set after the body 
is in place. (See Fig. 40.) When a.cove base is used 
it may be necessary to set it first, but in all cases must 
be well supported on the concrete. (See Fig. 41.) The 
strips must be placed plumb and even with the intend¬ 
ed finished wall line. The method of setting wall tile 
is governed to some extent by the conditions of the 
wall on which they are to be set, and must be decided 
by the mechanic at the time, which process he will 
use, whether buttering or floating, as equally good 
work can be done by either, by following the instruc¬ 
tions, as stated below. 

Floating Wall Tile .—The mortar is spread between 
the guide strips for about five feet at a time and lev¬ 
elled with a screed notched at each end to allow for 
the thickness of the tile. (See Fig. 39.) The tiles are 
placed in position and tamped until they are firmly 
united to the cement and level with the strips. When 
the space between the strips is completed, which should 
be one side of the room, the strips are removed and 
the work continued in the same manner until com¬ 
pleted. Wlien the tiles are all set, the joints must be 
carefully washed out and neatly filled with thinly 
mixed pure Keene’s Cement, and all cement remaining 
on the tile carefully wiped off. 

Buttering Wall Tiles .»—The cement mortar is spread 
on the back of each tile, and the tile placed on the 
wall, and tapped gently until firmly united to the wall 
and plumb with the guide strips. When the tiles are 
all set, the joints must be carefully washed out and 
filled with Keene’s Cement, and the tiles cleaned as 
directed above. 

When fixtures of any kind are to be placed on the 


492 


CEMENTS AND CONCRETES 


tile work, such as plumbing in bathroom, provision 
should be made for them by fastening wood strips on 
the wall before the rough or first coating of cement 
mortar is put on, the strips to be the same thickness 
as the rough coating. The tiles can be placed over 
the strips by covering them with cement mortar, and 
when thoroughly set, holes can be bored in the tiles for 
fastening the fixtures without injuring the tiling. 

Hearth and Facing Tile are set in the same manner 
as for floors and walls. 

Cleaning .—It is absolutely necessary to remove with 
sawdust, and afterwards with a flannel cloth and wa¬ 
ter, all traces of cement which may have been left on 
the surface of the tile, as it is hard to remove after it 
is set. 

After thoroughly cleaning the floor, it should be 
covered with sawdust and boards placed on the floor 
for several days where there is walking upon it. 

A white scum sometimes appears on the surface of 
the tile, caused by the cement. This can generally be 
removed by washing frequently with plenty of soap 
and water. If this does not remove it, then use a weak 
solution of 15 parts muriatic acid and 85 parts wa¬ 
ter, which should only be allowed to remain on the 
tile for a few minutes, and then thoroughly washed 
off. 

Cutting of Tile .—When it is found necessary to cut 
tile the following directions are given : 

Tools.*— The chisels used should be made of the best 
tool steel, and should always be sharp. They should 
be of small size, the edge not being wider than one- 
fourth inch. The hammer should be light, weighing 
about six ounces, having a slender handle. After the 


HOW TO USE THEM 


493 


exact shape of the tile has been determined, lines 
should be drawn on the surface of the tile with a lead 
pencil, giving the exact direction of the cut desired. 
This line should be followed with the chisel, which is 
held at right angles with the surface, the hammer 
giving the chisel sharp, decisive raps. After the line 
has been repeatedly traversed with the chisel, a few 
sharp blows against the back of the tile opposite the 
mark on the face will break it at the place thus 
marked. 

To cut glazed or enamel tiles, they should be 
scratched on the surface with a tool at the place where 
it is desired to break them, and then gently tapped 
on the back opposite the scratch. 

Caution should be used not to allow any one to 
walk upon or carry anything heavy over the floor, or 
have any pounding about wall work for several days, 
or until the tiles are firmly set. Unless these precau¬ 
tions are taken it will be impossible to guarantee a 
first-class job. Tile work is frequently condemned 
when the fault lies with the rush of other contractors to 
finish their work. 

Laying Tile on Wood .—A new material called 
“Monolith,” manufactured by The Wisconsin Mantel 
& Tile Co., that enables the workman to lay tiles on 
a wooden floor. There are many places where tile 
could be used, but on account of the added weight to 
the floor by the use of cement, concrete foundation, it 
is impracticable to lay in many places, but by the use 
of Monolith, the only weight that is added is the tile 
itself and the Monolith bed it is laid in. Both ma¬ 
terials are only five-eighths of an inch in thickness 
when laid. 


494 


CEMENTS AND CONCRETES 









HOW TO USE THEM 


495 


The illustration, Fig. 42, shows the method of laying 
the tile. The paper to which the small pieces of tiles 
are glued is seen on top of tiles. The dark part shows 
the patent cement, or Monolith. 

I show herewith, at Nos. 43 and 44, twelve designs 
for decorative borders of various kinds, and in 45 
and 46 I show two designs well suited for vestibules, 
store entrances or for hearths in fire-places. 

Good Concrete .—In determining the proportions of 
the aggregates and cement for a certain piece of work, 
it is necessary usually to take samples of the broken 
stone (or gravel) and sand which are most available 
to the site and make measurements of the percentage 
of voids in the stone which must be filled by the sand 
and the percentage of voids in the sand which must 
be filled by the cement. This is done by taking a 
cubic foot box and filling it with broken stone in a 
thoroughly wet state. The box is then filled with as 
much water as is required to completely fill it, in addi¬ 
tion to the stone, which upon being poured off gives 
the relation between the volume of the voids and the 
volume of the stone. The required amount of local 
sand thus determined is then measured out and placed 
in the box with the stone in a damp state. Water is 
then used to determine the percentage of voids left in 
the sand, which gives the approximate amount of 
cement required, although an excess of cement is al¬ 
most invariably used. Engineers everywhere differ 
regarding the best proportion to be used, but in gen¬ 
eral the above test, roughly made, will determine it 
well enough. The proportions which are most univer¬ 
sally used are as follows: 1 cement, 2 sand, 4 broken 
stone; where extremely strong work is desired. Tests 


496 CEMENTS AND . CONCRETES 



. :■ ■■ ... 


SoRDEB No. 411 




•r-rriT 


.yagam 








■£&?M 


Border No. 412 


m T m 


xrijan r 1t r r h h ti i r n, r i, rrr 


Border No. 413 


Border No. 414 


•. ■. ■ 


.. r < -, '? • 

Border No. 415 


Border No. 416 






• ww&KMvmm 

'..*;- • ••• '«, ,■• .- . • • ' -- ..?> 

'V •> & * •; V ^ >V%; & $<&-$$ • V * v r 

V/. 6*,6&4 <:• ###&& € ;'■«!#tfC-&* ^ r, •- ^ 

1 <#Ji4 #•& *>.• ■; « #«,*'*i ^ & «M*• #.*>& •#<&§ ******41 #T* S-##*£#« m- ;> ® 

%vjk? * v *w*«v»** **&&*■ 

•■&r • /./?:, • ■■<■;*<&. ■• >//♦ 

■**■ P'- ••’fey jevi •9**-v.‘ os****** «*•«•£*. «#,-?*• 

"»" < I’ - &-.’.>«*#/5S? M• »*<§» &iiQ<t+f3v A ' g 


Decorative Bonders in Round, Square and One Inch 
Hexagons of Various Colors. 


Fig. 43 


























































































































































HOW TO USE THEM 


497 



'■ fiK'' W.np • '• . ' „ '■ N --'- •' 

bA Wide. • Border, No. 54c 


Border No. 543 


8" Wide. 


Border No. 544 


■. « • „,r$ 

Border No. 545. 


9y Wipe. 


i 

IV'Wide. 

iiHtnuiiiiHnuii! 


> , 

Border No.. 548 


, • ’ . ■; :V- 


16" Wide. 










13" Wide. Border No 547 


A Series of Borders in Square Tiles, Each in. a 
Variety of Colors. 


Fig. 44- 










































































498 CEMENTS AND CONCRETES 

show that a 6-inch thickness of 1-2-4 concrete properly 
made is waterproof up to about 50 pounds to the square 
inch. This concrete is frequently used for facing* 
dams. 1-3-6 is the proportion generally used for the 
interior of dams and large structures. It is entirely 
suitable for large foundations. 1-4-8 is frequently 
used for foundation work, and when properly mixed 


Fig. 45. 

makes good concrete, although it is about the limit 
of what is considered good work, and would not be 
suitable for very important structures. 1-5-10 is equal 
to any concrete made with natural cement. It is a 
well-known fact that the volume of concrete when 
mixed with water is somewhat less than the volume of 
the aggregate and cement before mixing. The con¬ 
tractors’ rule is that the volume of mixed concrete is 





























HOW TO USE THEM 499 

equal to the volume of the stone plus one-half to one- 
third the volume of sand. 

There has been much discussion among engineers 
and others as to the amount of water that should be 
added to the aggregates and cement for making the 
best concrete, and while it is not the purpose of this 
paper to enter into this controversy, it might be said 
that the modern tendency is toward wet concrete. The 
old way was to add just enough water so that when all 


Fig. 46. 

the concrete was in the form and tamped, it would 
show moisture on the surface. The tamping is a very 
important part of the operation, and the quality of 
the work is dependent upon how well this is super¬ 
intended, as unless it is well and thoroughly done the 
concrete is liable to be honeycombed and imperfect, 
especially near the forms. With the growth of the 

















500 


CEMENTS AND CONCRETES 


use of concrete the old method of putting it in the 
forms nearly dry and depending on tamping to con¬ 
solidate it has been more or less abandoned, and the 
more modern way is to put the concrete in quite wet, 
as less tamping is required and much labor and ex¬ 
pense saved. One of the great objections to this 
scheme is that if care is not taken the water will tend 
to wash the cement from the stone and sand; in other 
words, unmix it. However, it may be said that it 
is now generally understood that rather wet concrete 
properly handled makes better work. The amount of 
water to be added to the aggregates and cement va¬ 
ries from 1 water to 3 cement by measurement to 12 
per cent of water by weight. Mr. Carey, of New- 
haven, England, says that 23 gallons water per cubic 
yard of cement was the best mixture. Quite frequent¬ 
ly salt water is used in mixing concrete in cold weather 
to prevent freezing, and it seems to have no ill effects 
on the resulting mixture. 

Reinforced Concrete .—Up to the last few years the 
use of concrete as a building material was chiefly con¬ 
fined to the construction of foundations, piers, reser¬ 
voir dams and similar purposes, in which the stresses 
to be met were almost entirely simple pressures. In¬ 
deed, even fifteen years ago, many engineers looked 
askance on the use of concrete for arches, considering 
it for this purpose much inferior to brick. Much of 
the caution shown in extending the use of this valua¬ 
ble material doubtless arose from the frequency with 
which concrete masonry exhibited unsightly cracks, 
due largely to the material being allowed to get too 
dry while hardening. At the same time, careful ex¬ 
amination has shown that cracks of the same char- 


HOW TO USE THEM 


501 


acter are common in masonry of all kinds, but are 
unnoticed, because they follow the regular joints of 
the structure; whereas, on the smooth uniform sur¬ 
face of the concrete, cracks of much less significance 
are immediately visible. 

The plan of reinforcing the material with metal, of 
which several systems have been introduced during 
the last four years, has greatly extended the possible 
use of concrete; and it appears that in many cases a 
reinforced concrete bridge may compete, even in first 
cost, with a steel girder; while as regards upkeep, it 
has, of course, many advantages. Small bridge cul¬ 
verts of this material were extensively used by Rus¬ 
sian engineers in building the Manchurian Railway. 
For openings of some 7-foot span, flat slabs of con¬ 
crete reinforced with rails were used, the thickness 
being 8% inches. A similar system was used for spans 
up to 21 feet, the concrete, however, being thickened 
at the center as the span increased, the depth at this 
point being 2 feet 6*4 inches for the 21-foot span, and 
proportionately less for smaller openings. The thick¬ 
ness at the bearings was, however, the same in all 
cases, viz., 8% inches. The line was thrown over the 
spans as little as seven days after completion. The 
concrete consisted of one part cement, two sand and 
five broken stone. The system in this case had great 
advantages, as stone for masonry was unobtainable, 
and could, moreover, only be used for arches, which 
would have necessitated the use of higher embank¬ 
ments than w^ere required with the ferro-concrete, used 
as described. Much larger spans have, of course, been 
built than those mentioned. One, of 153-foot span, 
carrying four main line tracks, has recently been 


502 


CEMENTS AND CONCRETES 


built for the Lake Shore and Michigan Southern Rail¬ 
road, while Mr. Edwin Thacker, M. Am. Soc. C. E., 
states he considers the system feasible for spans up 
to 500 feet, and has actually got out designs for a 
span 300 feet, the cost comparing favorably with that 
of a steel bridge. 

One great drawback to the extension of the system 
lies in the difficulty in proportioning structures thus 
built in a thoroughly rational manner. In the case of 
steel bridges certain simple assumptions as to the 
elasticity and strength of the material suffice. These 
assumptions are doubtless not absolutely exact, but are 
sufficiently near the truth for practical purposes. The 
elastic properties of concrete are, however, very dif¬ 
ferent from those of steel; Hooke’s law is not even ap¬ 
proximately correct, and, moreover, the material al¬ 
ways takes a permanent set when first loaded. The 
true distribution of the stress and strain on a concrete 
beam is thus a much more complicated matter than it is 
in the case of a steel joist, in which it is permissible, 
within working limits of stress, to assume the accuracy 
of Hooke’s law. The assumption generally made in 
the case of ferro-concrete is that plane sections of a 
concrete beam remain plane after bending. This pos¬ 
tulate is, of course, that commonly made in propor¬ 
tioning steel work; and in the latter case, stress being 
proportional to strain, the usual formula for the work¬ 
ing strength of beams is readily reduced. In the case 
of concrete, however, the stress-strain curve is much 
more complex. Nevertheless, M. Considere has shown 
that by making experiments on concrete in simple ten¬ 
sion and compression, and plotting the corresponding 
stress-strain curves, it is possible to deduce from these 


HOW TO USE THEM 


503 


with fair accuracy the load-deflection curve of a ferro¬ 
concrete beam. 

This method, though logical, leads, however, to no 
simple formula for the strength; and in applying this 
method the working load of any particular concrete 
beam would have to be deduced by the tedious proc¬ 
ess of scaling off the stress-strain curves at a num¬ 
ber of points, and combining the results. A further 
question arises as to whether this stress-strain curve 
should be the initial stress-strain of the concrete, or 
that obtained after repeated loadings. Probably the 
latter is the best to choose, but in that case it by no 
means follows that the metal reinforcement is free 
from initial stresses when the load is applied to the 
beam; and if the metal is subject to initial stress, it is 
obvious that similar ones must exist in the concrete. 
In fact, M. Considere has shown that this is necessarily 
the case in any circumstances, since, if the concrete is 
allowed to harden under water, it tends to expand, 
and this expansion is resisted by the metal reinforce¬ 
ment. If, on the other hand, the hardening takes 
place in air the concrete tends to contract; and this 
contraction being again resisted by the metal, a series 
of fine hair cracks are produced which, visible at low 
loads, are readily detected on the tension side of a 
heavily loaded ferro-concrete beam. 

In view of the uncertainties introduced by the dif¬ 
ferent factors above mentioned, it is really questionable 
whether, after all, the theoretically objectionable for¬ 
mula of M. Hennebique is not as good as any other. 
The latter all involve a preliminary calculation of the 
position of the neutral axis, which varies with the per¬ 
centage of metal used, and with the type of stress- 


504 


CEMENTS AND CONCRETES 


strain curve assumed for the concrete; and also with 
the maximum stress at any particular section. Thus, 
in a centrally-loaded beam, its position at the ends is 
entirely different from what it is at the centre. M. 
ITennebique, on the other hand, makes no attempt to 
locate this neutral axis, and simply assumes that one- 
half of his beam resists compression, and that the 
stress is uniformly distributed over this half. The 
moment of this compression about the centre of the 
section equates to half the moment due to the load, 
and the other half of the moment due to the load he 
equates to the moment about the centre of the section 
of the tensile stress on the metal reinforcement. The 
working strength of concrete in compression, he takes 
as 350 pounds per square inch, and neglects entirely its 
strength in tension. The working tensile stress on the 
steel reinforcement he takes as 14,000 pounds per 
square inch. This method is, of course, totally illogi¬ 
cal, yet many thousand cubic yards of ferro-concrete 
have been successfully designed on these lines; and a 
comparison of the strength of ferro-concrete beams 
as calculated by this formula, and by those of a more 
rational type, shows very little difference between the 
two for a considerable range of metal to concrete. On 
the other hand, it must not be forgotten that formulae 
which are non-rational in form are always risky when 
applied to extreme conditions. 

Concrete being as weak in shear as in tension, pro¬ 
vision is also required to take the shearing stresses. 
Some American designers have to this end patented 
special forms of reinforcement bar, in which each main 
tension bar has projecting upward from the ties in¬ 
clined at an angle of 45 degrees. These extend to the 


HOW TO USE THEM 


505 


top of the bar and take the tensile stresses arising 
from the shear. The corresponding compressive stress 
at right angles to this is carried by the concrete. The 
system is doubtless efficient, and on large spans, where 
weight must be reduced to a minimum it may have 
some advantage; but in work of ordinary proportions 
it seems to be little superior to the Hennebique sys¬ 
tem, in which the necessary strengthening is provid¬ 
ed by stirrups of flat iron bent into a U shape. The 
main reinforcing bars rest in these stirrups at the 
lower ends. The spacing of the stirrups depends upon 
the “web stresses” to be taken, which can easily be 
calculated by assuming the reinforced beam to be a 
latticed girder, the.lower chord of which is represented 
by the metal reinforcement, the upper one by the centre 
of the compression half of the beam, while the stirrups 
represent vertical ties, which may be taken as con¬ 
nected together at top and bottom by'inclined imag¬ 
inary struts. The advantage of this simple method of 
reinforcing for shear lies in the possibility of using 
common rolled sections for the whole of the rein¬ 
forcement. 

M. Hennebique constructs most of his ferro-concrete 
work on the monolithic system, girders, piers, columns 
and floors being solidly connected together. It is, 
therefore, necessary to provide for the reversed bend¬ 
ing moments'over the point of support, which is done 
by bending up half of the total reinforcement bars, 
so that the ends of the span are close to the upper 
surface of the beam, and thus in a position to take 
the heavy tensile stresses which ensue at these points 
when the monolithic system of construction is fol¬ 
lowed. The exact calculation of the reactions and 


506 


CEMENTS AND CONCRETES 


bending moments here is impracticable, if not actually 
impossible; and those engineers who attach much im¬ 
portance to having all structures statically determinate 
will doubtless object to the plan, but experience shows 
that the advantages gained are very considerable. The 
structure then resists as a unit, and in particular its 
rigidity is marvelous. 

Some comparative tests on this point, made by the 
Railway Company, showed that with a ferro-concrete 
floor subjected to blows four times as heavy as were 
applied to an equivalent floor constructed of brick 
arches on steel joists, the deflection was only one- 
seventh as great. 

The extreme rigidity attainable with the monolithic 
system of construction was also very evident in the 
case of the large Hennebique bridge at Purfleet. Since 
a structure fails by strain rather than by stress, the 
small deformation noted with ferro-concrete are evi¬ 
dent that as an average the material is relatively lit¬ 
tle tried by the loads carried. It must, however, be 
admitted that this low average strain is quite com¬ 
patible with extremely severe strain at particular 
points; but it is, of course, the business of the designer, 
by suitably disposing his material to avoid these pos¬ 
sible local abnormalities. 

Occasionally, doubts have been expressed as to 
whether the metallic reinforcement may not suffer from 
corrosion as time goes on. This would be extremely 
dangerous if it occurred, since the metal being out of 
sight, its loss of strength might remain undetected un¬ 
til, some day, the structure might fall under its ordi¬ 
nary working load. Fortunately, much evidence is 
available to the effect that steel or iron thoroughly 


HOW TO USE THEM 


507 


imbedded in concrete is permanently protected from 
rnst. Americans, indeed, are so positive on this point 
that they have recently constructed a number of reser¬ 
voir dams in ferro-concrete. In some cases these have 
been arched, but in others they have been straight. 
The cross-section in the latter case is generally a hollow 
triangle, the sides of which are connected together by 
diaphragm walls from point to point. The dam is also 
anchored to its site, though generally the weight pro¬ 
vided is sufficient to make the structure safe against 
overturning, quite apart from the help received from 
the anchor-bars. 

Progress in the use of reinforced concrete has been 
somewhat slow in England. The railway engineers, in 
view of their enormous responsibilities, have not un¬ 
naturally hesitated to adopt a material in which it was 
impossible to calculate the strength with accuracy, and 
of which experience as to its reliability was very re¬ 
cent. In the larger cities, moreover, its use has, quite 
apart from this, been restricted by the inelastic na¬ 
ture of the building regulations, which have been 
reached upon the assumption that finality had been 
reached in the matter of building construction. Hence, 
permission to erect warehouses and factories in ferro¬ 
concrete has always been difficult—and often impossi¬ 
ble—to obtain, though experience has shown that the 
new material is most excellent as a fire-resister. At 
the great Baltimore fire it was found that the concrete 
exposed to the flames was seldom damaged to a greater 
depth than one-half inch, though projecting corners 
suffered somewhat more, being rounded off by the 
flames to a radius of about two inches, pointing to the 
advisability of constructing the concrete with well- 


508 


CEMENTS AND CONCRETES 


rounded corners in the first instance. The only rea« 
sonable grounds of objection to any proposed system 
of building construction are its dangers from a struc¬ 
tural sanitary or fire-risk point of view. As a result 
of much investigation and experiment, the following- 
conclusions were arrived at for the guidance of the 
designer and constructor of reinforced concrete: 

1. What drawings and details should be prepared 
before work is commenced. 

2. The nature of the materials which may be em¬ 
ployed and the standards to which these should com- 
ply, i. e., 

(a) the metal in reinforcement, 

(b) the matrix, 

(c) the sand, 

(d) the gravel, stone, clinker or other aggregate, 

(e) water. 

3. What are the proportions for concrete to be used 
in different cases. 

4. How the ingredients for concrete are to be mixed 
and deposited on the work. 

5. The distances to be allowed between the reinfor¬ 
cing bars and what covering of concrete is necessary. 

6. What precautions are necessary in the design and 
erection of centring and false work, and how long the 
whole or portion of centring and false work should re¬ 
main in position. 

7. The rules which should be used in determining 
the dimensions of the several parts necessary for secur¬ 
ity, and what safe stresses should be allowed. 

8. The supervision necessary and the special matters 
to which it should be directed. 


HOW TO USE THEM 


509 


9. The fire-resisting properties of reinforced con¬ 
crete. 

10. Its adaptability for structures where resistance 
to liquid pressure is essential, and what special precau¬ 
tions may be advisable under these conditions. 

11. What are the necessary conditions for its perma¬ 
nence ; resistance to rusting of metal, disintegration of 
concrete or effects of vibration. 

12. The testing of the materials employed and of the 
finished structures. 

13. What provisions are desirable in Building Laws 
or Government regulations relating to buildings and 
other structures so far as these affect the use of rein¬ 
forced concrete. 


INDEX 


PAOS 

MATERIALS: 

Limes . 21- 

Cements . 30 

Mortars . 28 

Sand . 28 

Plasters and laths. 31 

WORKMANSHIP: 

External work . 35 

Internal work . 37 

SPECIFICATION CLAUSES: 

Materials . 42 

Workmanship . 43 

PREPARATION OF BILL OF QUANTITIES: 

Materials . 46 

Workmanship . 46 

Laths . 48 

TOOLS AND APPLIANCES: 

Hoes and drags. 50 

The hawk . 52 

The mortar board.,.. 52 

Trowels . 52 

Floats . 52 

Moulds . 54 

The pointer. 54 

The paddle . 55 

Stopping and picking out tools. 55 

Mitering rod. 55 

Scratcher . 55 


























INDEX 


PAGH 

TOOLS AND APPLIANCES.—Continued. 

Hod . 55 

Sieve. 56 

Sand screens . 56 

Mortar beds . 57 

Slack box. 57 

Lathing . 57 

Lather’s hatchet.. 58 

Nail pocket . 58 

Cut-off saw .. 58 

PL ASTER, LIME, CEMENTS, SAND, ETC.: 

Plaster of Paris. 60 

. Quick and slow setting plaster. .62 

Testing . 63 

French plaster. 65 

Limes . 65 

Hydraulic limes . .... 66 

Calcination. 69 

Slaking . 70 

Mortar . 73 

Hardening of mortar. 78 

Magnesia in mortars. 82 

Effects of salt and frost in mortar. 84 

Sugar with cement. 86 

Sugar in mortar... 88 

Lime putty . 89 

Setting stuff. 90 

Haired putty setting. 91 

Lime water .. • 91 

Hair . 91 

Fibrous substitutes for hair. 92 

Sawdust as a substitute for hair. 93 

Sand . 94 

Mastic . 96 

Scotch mastic . 96 

Common mastic .. ... • 97 

Mastic manipulation. 97 






































INDEX 


PAGE 

PLASTER, LIME, CEMENT, ETC.—Continued. 

Hamelein’s mastic .. 97 

Mastic cement . 98 

TERMS AND PROCESSES ? 

Three-coat work. . 99 

First coating. 99 

Scratching ....... 100 

Rendering . ____.,. 102 

Screeds .. 103 

Floating ... 103 

Flanking . 106 

Scouring coarse stuff.. ill 

Keying .....'. 112 

Setting. 114 

Laying setting stuff. 115 

Scouring setting stuff. 115 

Troweling and brushing setting stuff. 116 

General remarks on setting. 117 

Common setting . 119 

Skimming . 119 

Colored setting. . 119 

Gauged setting. 120 

Gauged putty set. 120 

Putty set... 121 

Internal angles . 121 

External angles . 121 

Skirtings . 122 

Two coat work. 123 

One-and-a-half coat work. 123 

Stucco . 124 

Old stucco ... 124 

Common stucco .. 129 

Rough stucco .. 129 

Bastard stucco . 130 

Troweled stucco . 130 

Colored stucco. 131 

Method of working cements -..131 






































INDEX 


PAGE 


TERMS AND PROCESSES.—Continued. 

White cement efflorescence. 

Cornice brackets. 

Cornices. 

Mitring. 

Mitre mould . 

Fixing enrichments. 

Mitring enrichments . 

Pugging . 

Sound ceilings . 

Cracked plaster work. 

Repairing old plaster. 

Gauged work. 

Joist lines on ceilings. 

Rough casting .. 


138 

139 

140 

155 

156 

159 

160 

163 

164 

165 
165 
168 

169 

170 


VARIOUS METHODS OF RUNNING COR¬ 
NICES, CIRCLES, ELLIPSES AND OTHER 
ORNAMENTAL STUCCO WORK: 

Diminished columns . 

Column trammel . 

Constructing plain diminished columns. 

To set out the flutes of diminished columns- 

Constructing diminished fluted columns. 

Forming diminished fluted column by the rim 

method . 

Running diminished fluted column by the Col¬ 
lar method .. 

Diminished fluted pilasters. ... 

Pannelled coves .. 

Diminished mouldings .. 

False screed method... 

Running double diminished mouldings. 

Diminished rule method. 

Top rule method... 

Cupola panels and mouldings:. 

Panelled beams. 


177 

180 

183 

183 

185 

193 

196 

200 

200 

204 

204 

208 

208 

211 

215 

220 































INDEX 


PAGE 

VARIOUS METHODS, ETC.—Continued. 

Trammels for elliptical mouldings. 220 

Templates for elliptical mouldings. 224 

Plasterer’s oval . 228 

Coved ceilings. 233 

Circle mouldings on circular surfaces.. 233 

Forming niches . 235 

Running an elliptical moulding in situ. 240 

MISCELLANEOUS MATTERS: 

Depeter . 243 

Sgraffitto . 243 

Fresco . 251 

Fresco secco . 255 

Indian fresco and marble plaster. 256 

Scagliolia . 260 

Artificial marbles. 262 

Pick’s neoplaster . 263 

Scagliolia manufacture . 264 

Mixing . 270 

Colors and quantities. 272 

Polishing white scagliolia. 275 

Polishing scagliolia . 276 

Marezzo . 277 

Granite finish. 282 

Granite plastering . 283 

CEMENTS AND CONCRETES AND HOW TO 

USE THEM: 

Fine concrete. 291 

Matrix . 293 

Aggregate . 294 

Porous aggregates . 295 

Compound aggregates. 296 

Sand and cement .U. 297 

Fire-proof aggregates . 300 

Voids in aggregates. 302 

Crushing strength of concrete.302 

































INDEX 


PAGE 

CEMENTS AND CONCRETES.—Continued. 

Water for concrete. 303 

Gauging concrete. 305 

Ramming concrete. 308 

Thickness of concrete paving.. 309 

Concrete paving. 310 

Eureka paving . 312 

Eureka aggregate. 313 

Eureka quantities .’.. 314 

Levels and falls. 315 

Pavement foundations. 316 

Screeds and sections. 318 

Laying concrete pavements. 320 

Troweling concrete . 321 

Grouting . 322 

Dusting. 322 

Temperature . 322 

Non-slippery pavements . 323 

Grooves and roughened surfaces. 323 

Stamped concrete . 325 

Expansion joints . .. .. 325 

Washing yards ....328 

Stable pavements. 328 

Concrete slab moulds. 329 

Slab making . 330 

Induration concrete slabs. 330 

Mosaic . 331 

Concrete mosaic. 333 

Concrete mosaic laid in situ. 334 

Storing cement .. 337 

Cement mortar. 337 

Mixing .V.... 338 

Grout . 339 

Lime and cement mortar. 339 

Cement mortar for plastering. ... 339 

Materials for making concrete sand. 340 

Gravel ... • • 341 






































INDEX 


PAGE 

CEMENTS AND CONCRETES.—Continued. 

Crushed stone. 341 

Stone versus gravel. 342 

Cinders .. 342 

Concrete . 343 

Proportioning materials . 344 

Aggregate containing tine material. 345 

Mechanical mixers . 346 

Mixing by hand.. 346 

Consistency of concrete. .. 347 

Use of quick setting cement.. 347 

Coloring cement work. 347 

Depositing concrete. 348 

Retempering . 349 

Concrete exposed to sea-water. 349 

Concrete work in freezing weather. 350 

Rubble concrete. 350 

To face concrete.. 351 

Wood for forms. 352 

Concrete sidewalks .. 352 

Excavation and preparation of subgrade. 353 

The subfoundation. 353 

The foundation . 353 

The top dressing or wearing surface. 354 

Details of construction. 384 

Concrete basement floors. 358 

Concrete stable floors and driveways. 358 

Concrete steps . 359 

Reinforced concrete fence posts. 360 

Reinforcement ..... 362 

Concrete for fence posts. 362 

Molds for fence posts. 363 

Attaching fence wire to posts. 365 

Molding and curing posts. 365 

Concrete building blocks. 368 

Tests of concrete fence posts... 370 

Retempering . 378 






































INDEX 


PAGB 

CEMENTS AND CONCRETES—Continued. 

Some practical notes. 380 

Concrete stairway and steps. 387 

Cast concrete stairs. 389 

Test of steps. 390 

Concrete stairs formed in situ. 391 

Setting out old stairs. 391 

Nosings and risers. 392 

Framing staircases . 394 

Centring for landings and soffits. 396 

Waterproof centring. 397 

Staircase materials . 399 

Filling in stairs. 400 

Finishing stairs . 404 

Non-slippery steps. 405 

Striking centrings. 405 

Concrete and iron. 406 

Setting concrete soffits. 408 

Fibrous concrete .• • • 408 

Polished soffits . 409 

Concrete staircases and fibrous plaster. 410 

Dowel holes. 410 

Cast steps .. 411 

Treads and risers. 412 

Closed outer strings. 413 

Concrete floors . 413 

Plaster floors . 415 

Joist concrete floors. 416 

Caminus concrete cement. 417 

Concrete floors and coffered ceilings. 418 

Combined concrete floors and panelled ceilings. 419 

Concrete and wood. 420 

Concrete drying.. 421 

Concrete slab floors. 423 

Construction of slab floors. 425 

Hollow floors .. 427 

Concrete roofs . 428 





































INDEX 


PAGE 

CEMENTS AND CONCRETES.—Continued. 

Notes on concrete. 429 

Cast concrete . 431 

Concrete dressing . 432 

Mouldings cast in situ. 438 

Modelling in fine concrete.. 443 

Concrete fountains . .-. 446 

Concrete tanks . 446 

Concrete sinks. 448 

Garden edging . 448 

Concrete vases . .. 448 

Concrete mantel pieces. 449 

Colored concrete. 449 

Fixing blocks . 452 

Typical system of reinforced concrete construc¬ 
tions from various sources. 452 

Columns and piles. 458 

Floors, slabs and roofs. 468 

Beams .. 469 

Arches . 471 

Lintels . 473 

Concrete walls . 475 

Strong rooms . 475 

Concrete coffins and cementation... 475 

Tile fixing. 477 

Setting floor and wall file. 479 

Foundations . 479 

Lime mortar. 480 

Concrete. 480 

For floors. 480 

For wood floors. 480 

In old buildings. 481 

For hearths . 482 

For walls .-. 484 

Cement... 486 

Sand . .. 486 

Mortar . 486 





































INDEX 


PAGE 

CEMENTS AND CONCRETES.—Continued. 

Soaking* . 486 

Tiles for floors. 486 

Ceramics . 488 

Files for walls and wainscoting.490 

Floating wall tile. ... 491 

Buttering wall tiles. 491 

Hearth and facing tile.. 492 

Cleaning.492 

Cutting of tile. 492 

Tools. 492 

Laying tile on wood. 493 

Good concrete. 495 

Reinforced concrete. 500 
















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and useful memoranda. GUIDE TO CORRECT 
MEASUREMENTS is found in the second part of 
this work. This shows how all kinds of odd, crooked 
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No. 3R9120 BUILDERS’ RELIABLE ESTIMATOR 
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SEARS, ROEBUCK & COMPANY, 
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